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Skywatch 2015
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Albany Clear Sky Clock

Skywatch Line scripts are written by members of the Albany Area Amateur Astronomers. They can be heard by calling 518-382-7890 ext. 229. Scripts are copyrighted and may not be reproduced without permission.

Call 518-382-7890 extension 229 to hear the current Skywatch Line

This is Dudley Observatory’s Skywatch Line for Friday, May 22, through Sunday, May 24, written by Alan French.

Reaching new very late last Sunday and reaching first quarter this coming Monday, a waxing crescent Moon will grace the evening sky. The Moon sets just after midnight on Friday night, at 12:44 am on Sunday, and not until 1:16 am on Monday.

With the Moon conveniently placed in the sky just after dark, this would be a lovely weekend to explore the lunar landscape with a telescope. Any telescope will reveal a wealth of detail, especially along the terminator, the line dividing the sunlit portion of the Moon from the portion still in lunar night.

If you have a telescope outside around 9:00 pm, also take a look at Jupiter. On Friday night all four visible moons will be stretched out to the west (right) of the planet. In order of distance, from closet to farthest, they will be Europa, Io, Ganymede, and Callisto, with Europa and Io quite close together.

Saturday night will find Io and Europa to Jupiter’s east, and Ganymede and Callisto to the west. Sunday at 9:00 pm Io and Callisto will be to the west and Ganymede to the east, but Europa will be absent – passing in front of the planet where it is very hard to spot. Its shadow, which appears as an inky black dot and is easier to see, will move onto the planet at 10:46 pm, and Europa will move out from in front of Jupiter at 11:13 pm. (If you find the moons positions backwards, it’s because you have a telescope that reverses the view, like a refractor with a star diagonal).

For naked eye skywatchers, note the Moon’s motion among the bright planets. On Friday night as darkness falls the Moon will be toward the west with Venus to its right and Jupiter to its upper left. Adding to the scene will be the bright stars Castor and Pollux above Venus and Procyon below the Moon.

By Saturday the Moon’s eastward motion against the stars will have brought it close to Jupiter, with only six degrees between the pair. Sunday will find the Moon well to Jupiter’s left, with the bright star Regulus, the luminary of Leo, the Lion, above the Moon.

The Dawn spacecraft has returned new images of the bright spots on Ceres, the largest asteroid. The new images show one of the spots is made up of smaller spots. Astronomers speculate they may be water ice, but we’ll have to be patient for a definitive answer.

The New Horizons spacecraft, approaching distant Pluto, has taken photographs of all five know moons orbiting the dwarf planet. Perhaps in the coming weeks, as it closes in on Pluto, some new moons will be discovered.

This is the Dudley Observatory Skywatch Line for Wednesday, May 20th and Thursday, May 21st written by Louis Suarato.

Wednesday evening features two planets, a crescent Moon and bright stars over the western horizon after sunset. The 10% illuminated, waxing crescent Moon will be about 12 degrees below Venus and at the feet of the Gemini twins around 9 p.m. above the west-northwest horizon. Thursday night, Venus will be 8 degrees north of a broader crescent Moon. Above Venus are Gemini's brightest stars, Pollux and Castor. The bright star, lower on the western horizon, is the star, Procyon, the brightest star in the constellation Canis Minor, and the eighth brightest star in our night sky. Procyon is a double star, consisting of a main star known as Procyon A, and a faint white dwarf known as Procyon B. Procyon's brightness is due to its near proximity to our Sun, about 11.46 light-years away, one of our closest stellar neighbors. To the south of Gemini, in the constellation Cancer, you'll find Jupiter. Jupiter and Venus are now 30 degrees apart. If you look at Jupiter through a telescope as the sky darkens around 9 p.m., you'll see a double transit of two of its Moons as Io leads Callisto across the face of the planet until 9:09 p.m., leaving Callisto and Io's shadow behind. Approximately 7 degrees directly below Jupiter is the open cluster M67. Discovered by Johann Gottfried Koehler in 1779, M67 is estimated between 3.2 and 5 million years old and 2,700 light years away, making this one of the closest, old open clusters. Turn to the southeastern horizon to view Saturn rising above Scorpius. Saturn comes to opposition on the night of May 22nd and will shine at magnitude 0.80 with its rings tilted 24 degrees toward Earth.

May 20th is the birth date of American astronomer George Phillips Bond. Born in 1825, Bond was the first to photograph a double star. Bond also discovered several comets, and, with his father, discovered Hyperion, the eighth moon of Saturn. May 20th is also the anniversary of the Hubble Space Telescope's first photograph, an image of the double star in the Carina cluster, sent to Earth in 1990.

This is the Skywatch Line for Monday and Tuesday, May 18th and 19th written by Joe Slomka.

The Sun sets at 8:14 PM; night falls at 10:16. Dawn breaks at 3:27 AM and ends with sunrise at 5:29.

The Moon turned "New" early Monday morning and is possibly visible very low in the western twilight sky. Binocular or telescopic observers can try if they have an unobstructed western horizon. The thin sliver of Moon, about 1 percent illuminated, lies about five degrees above the horizon and sets at 8:48 PM. Tuesday evening sees a fatter Moon about nine degrees high and setting about 9:48 PM. The thin crescent Moon appears about six degrees to Mercury's lower left.

Brighter Mercury appears higher in the western sky and is about eleven percent illuminated. In a telescope, the observer can compare Mercury's crescent with the Moon's. Both are lit by the Sun and both bodies' appearance depends upon Earth's viewing angle with the Sun. Mercury sets about 9:30 PM.

Venus, in Gemini and the brightest object, blazes moderately high in the West. In binoculars or telescope, it, too, displays phases. It appears about sixty percent illuminated and sets at 11:52 PM.

Jupiter is the second brightest and appears high in Cancer. It is about fifty degrees high in the southwest. Notice that the gap between Venus and Jupiter is slowly closing. Jupiter's time in the sky is shortening. At 12:23 AM Tuesday, a telescopic observer can see the Jovian moon Io's shadow begin its march across the planet; however, Jupiter sets while this is still in progress. Also on Tuesday, at 9:43 PM, Io itself is eclipsed by Jupiter's shadow. Jupiter sets at 1:30 AM.

Saturn rises in the East before Sunset. By civil twilight, it lies about four degrees above the horizon. It appears as the brightest object in Libra. Like Mercury, it may require a clear horizon to find it. Saturn is best observed at about 1:10 AM, when it is highest, and sets at 6 AM.

Neptune rises about 2:34 AM in Aquarius. At first light, the eighth magnitude planet may be spotted about 10 degrees above the eastern horizon.

Followers of the Skywatch Line know that the Milky Way represents the plane of our galaxy. They also know that the faint glow in Andromeda is that of a giant galaxy, similar to ours. These "island universes" are not isolated from each other. Their gravitational fields clump galaxies into groups. Recently, RPI's Doctor Heidi Newberg and her associates made new discoveries about our home galaxy, the Milky Way. They discovered that the Milky Way is larger than we assumed and contains newly discovered structures. Doctor Newberg, who is also president of the Dudley Observatory, will present a talk at the Albany Area Amateur Astronomer's monthly meeting at miSci on Thursday, May 21 at 7:30 PM. The public is invited and all club activities are free and open to the public.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, May 15, through Sunday, May 17, written by Alan French.

Reaching new very late Sunday, a slender waning crescent Moon rises just before the Sun and by Saturday morning is likely to be too deep into morning twilight to spot.

Jupiter, high in the west southwest as darkness falls, is in the constellation Cancer, the Crab, and provides a nice landmark for locating the Beehive.

Once the sky is dark, point your binoculars at Jupiter and carefully focus. Now place Jupiter in the upper left side of your field of view, and then move to the lower right. You should quickly bump into a lovely, loose sprinkling of stars. This open star cluster is the Beehive or Praesepe. It is faintly visible to the unaided eye and has been known since ancient times. It is one of the closest star clusters. To amateur astronomers it is also known as M44, meaning it is the 44th object on a list compiled by comet hunter Charles Messier. He cataloged some of the most impressive “deep sky objects” while searching for comets.

Dudley Observatory will hold an Octagonal Barn lecture and star party at 8:00 pm on Friday, May 15. The speaker will be Matthew Szydagis, Assistant Professor of Physics at the University of Albany, who will talk about “The Cosmic Dark Matter and Liquid Xenon.” The majority of matter in our universe is not in the form of stars, gas, or dust, but is what astronomers call dark matter. Professor Syzdagis will talk about xenon-based dark matter detectors and his work toward the next generation detectors.

The lecture will be held rain or shine. Weather permitting; it will be followed by a public star party. Guests are welcome to bring their own telescopes or to simply enjoy views through telescopes provided by Dudley Observatory and members of the Albany Area Amateur Astronomers.

The barn is located at 588 Middle Road, Delanson, New York 12053

Weather permitting the Albany Area Amateur Astronomers and NYS Parks will hold a public star party at 8:45 pm on Friday, May 15, in the Deerfield Pavilion area at Grafton Lakes State Park. Telescopes will be provided by members of the Amateur Astronomers and will provide guests with views of Jupiter, star clusters, double stars, and galaxies.

If you arrive after dark please use the winter entrance and follow the signs. In the event of heavy clouds or rain, the star party will be moved to Saturday – weather permitting. For more information or if the weather is uncertain, call one of the Star Party Coordinators: Bernard at 658-9144 or Ray at 658-3138. For directions call the park office at 279-1155 or use the address 100 Grafton Lakes Star Park Way, Grafton, NY.

This is the Dudley Observatory Skywatch Line for Wednesday, May 13th and Thursday, May 14th written by Louis Suarato.

The 25% illuminated, waning crescent Moon sets around 3 o'clock Wednesday afternoon. The Moon reaches perigee, 227,437 miles from Earth, its closest point during this lunar cycle, at 8:18 p.m. on Thursday. Sunset occurs 6 minutes after 8 p.m. in the west-northwest. Look for Mercury 10 degrees above the west-northwest horizon approximately 45 minutes after sunset. You'll find Venus about 20 degrees to Mercury's upper left. Jupiter, second only to Venus' brightness, will be higher to Venus' upper left in the constellation Cancer, very close and left of the Beehive Cluster, or M44. Jupiter's largest moon, Ganymede, partially occults Callisto Wednesday night at 11:07 p.m. EDT. Saturn rises in the southeast at 8:45 p.m., as Mercury is setting. Saturn remains between Libra and the head of Scorpius, and reaches its highest point around midnight. Saturn's rings are tilted 24 degrees from edgewise. Small telescopes will reveal the dark Cassini Division that separates the outer ring A from the brighter B ring. Look for Saturn's moons Titan, Tethys, Dione, and Rhea which will also appear in small telescopes. Saturn will be at its brightest when it reaches opposition (directly opposite the Sun) on May 22nd.

If you are a galaxy hunter, look above and below the last star of the Big Dipper's handle for three popular galaxies. The last star of the Big Dipper's handle is known as Alkaid. Alkaid shines at magnitude 1.85. While the Big Dipper is horizontal with the bucket down, as it is now, look three degrees below Alkaid for M101, or the Pinwheel Galaxy. The Pinwheel Galaxy, discovered by Pierre Méchain in 1781, is a face-on spiral galaxy 21 million light years away. Two degrees above Alkaid is M51, the Whirlpool Galaxy. The Whirlpool Galaxy, discovered by Charles Messier in 1773, is estimated to be approximately 23 million light years from the Milky Way galaxy. The Whirlpool Galaxy is accompanied by a smaller galaxy, NGC 5195. The two galaxies are interacting, and it is believed, the smaller galaxy maybe passing through the Whirlpool Galaxy. Three degrees above the Whirlpool Galaxy is M63, or the Sunflower Galaxy. The Sunflower Galaxy, discovered by Pierre Méchain in 1779, is also a spiral galaxy, estimated to be 25 million light years away. Features of the Sunflower Galaxy include small spiral arms and dark dust lanes.

The Dudley Observatory invites you to join them for an Octagonal Barn Lecture and Star Party Friday, May 15, beginning at 8 pm. Matthew Szydagis, Assistant Professor of Physics, University at Albany, will be giving a lecture on "The Cosmic Dark Matter and Liquid Xenon". The Octagonal Barn is located at 588 Middle Road, Delanson, New York 12053. Weather permitting, a star party will follow the lecture. Also on Friday, the Albany Area Amateur Astronomers will be hosting a star party at Grafton Lakes State Park. Direction to the park can be found at http://www.dudleyobservatory.org/AAAA/Directions.html.

This is the Skywatch Line for Monday and Tuesday, May eleventh and twelfth written by Joe Slomka.

The Sun sets at 8:07 PM; night falls at 10:04. Dawn breaks at 3:39 AM and ends with the Sun rising at 5:36.

Fading twilight reveals three bright planets in the western sky. Mercury is the lowest and third brightest. It hovers about 12 degrees above the horizon. In a telescope and under high powers, it appears about one-quarter illuminated. Mercury is already starting to fade in brightness and altitude. By month's end, it will be lost in the solar glare. Mercury sets about 10 PM.

Venus lies about 24 degrees to Mercury's upper left. Now in Gemini, Venus stays about three degrees from M-35, an open star cluster. Both should fit within a binocular or finder scope view. Venus blazes at minus 4.2 magnitude, M-35 is only sixth. Venus appears about two-thirds illuminated; the cluster resembles a scattering of diamonds on black velvet. Binoculars are the ideal instrument to behold this sight. Venus sets at 11:49 PM.

The highest of the trio, Jupiter, in Cancer, is second brightest at minus 2 magnitude. During civil twilight, Jupiter was at its peak. The giant planet is also heading eastward, away from the Beehive star cluster – another great binocular object. At 10:26 PM Monday, telescopic observers will see the moon Io begin to cross the planet's face, followed by its shadow at 11:42. At 12:43 AM on Tuesday, sky watchers will witness Io exiting the planet's face, followed by the shadow. Jupiter sets at 1:55 AM.

Nightfall sees Venus quite low in the West, while Saturn rose at 8:49 PM and appears as an extra star in Scorpius. Saturn is only zero magnitude. Of course, Saturn is a must-see because of its glorious rings. Saturn remains up the rest of the night.

The Last Quarter Moon rises around 2:18 AM. It appears about 40 percent lit on Tuesday morning, and about 30 percent Wednesday.

By first light, the Moon appears about 8 degrees from the distant planet Neptune, which rose shortly after moonrise. Neptune appears as a tiny blue-green dot to the Moon's lower left. Both share quarters in Aquarius and remain up the rest of the night.

One of the astronomical clichés is that Jupiter's Great Red Spot has been continuously observed for three centuries. While true, the Spot has been known to change. For example, it is not exactly red now, but closer to a salmon color. When measured in the 1800's, the storm was 25,000 miles wide. In 1979, the Voyager spacecraft imaged it at 15,534 miles. British astronomer John Rogers, in collaboration with professional and amateur astronomers, now measures it at about 12,500 miles. He also reports that wind speeds are increasing. The Great Red spot now has 300 miles-per-hour winds, up from 250. Like an ice skater, it spins faster as it gets smaller. Rogers speculates that, by 2050, it may be known as the Great Red Circle.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, May 8, through Sunday, May 10, written by Alan French.

If you look toward the southwest at 9:30 pm you’ll see bright Jupiter. Look to the left (east) of Jupiter for a bright star. This is Regulus, marking the heart of Leo, the Lion. The name was given to the star by Copernicus. It is Latin for “prince” or “little king.” A backwards question mark of stars rises above Regulus, outlining the Lion’s head. To the upper left of the backwards question mark, a triangle of stars marks his hindquarters. The easternmost and brightest star in the triangle is Denebola, which means “tail of the Lion.”

Leo is an ancient and well known constellation. It is one of the 48 constellations listed by the Greek astronomer Ptolemy in the second century, but it dates back at least a thousand years earlier to the Babylonians.

The sky lion, honoring the king of beasts, is usually associated with the Nemean lion. Nemea was a small town in southern Greece. A lion lived in a nearby cave and was carrying off town residents. With the town’s population decreasing rapidly, Hercules, in the first of his twelve labors, killed the lion.

Reaching last quarter early on Sunday, a waning gibbous Moon rises late. The Moon rises at 12:15 am Saturday, 1:00 am Sunday, and 1:41 am Monday.

Weather permitting the Albany Area Amateur Astronomers will take advantage of the dark evening skies by hosting two public star parties at Landis Arboretum in Esperance this weekend. At star parties club members set up a variety of telescopes and show guests some of the celestial showpieces. Star parties are canceled if the skies are mostly cloudy. If the weather is uncertain, you should call 374-8460 to verify that the star party is being held. Call after 6 pm. (Call earlier if you have questions about the star party.)  

The star parties will be held at 9:00 pm on Friday, May 8, and Saturday, May 9. They are usually held in the Meeting House field, which is on the right about 100 feet after you pass the Arboretum’s farmhouse, also on your right, on Lape Road. On rare occasions star parties are moved to the farmhouse area, so watch for a sign as you pass the farmhouse and main parking area. You can find directions at the Landis Website.

Jupiter is well placed for evening viewing now, and guests at the star party will enjoy views of our largest planetary neighbor. Telescopes easily show its four bright moons, although one will be hidden behind the planet Friday, and some features in its turbulent upper atmosphere.

Guests of all ages are welcome at star parties. There is no fee, although we encourage guests to make a donation to our fine host, the Landis Arboretum.

The Dudley Observatory Skywatch Line for Wednesday, May 6th and Thursday, May 7th written by Louis Suarato.

Wednesday, after sunset, look for Mercury 22 degrees to the lower right of -4.2 magnitude Venus over the west-northwest horizon. Thursday, look for the open star cluster, M35, 2.5 degrees to the left of Venus. Mercury reaches its greatest eastern elongation Wednesday at 21 degrees from the Sun, and shines at .2 magnitude. At twilight, Jupiter appears high above the southwestern horizon in the constellation Cancer. Leo's brightest star, Regulus, will be to the south of Jupiter. Jupiter is approximately 45 degrees from Venus and will be 21 degrees to Venus' upper left by month's end. Saturn rises at 9:13 p.m. in Scorpius. The span between rising Saturn in the east and Mercury setting in the west, is 173 degrees. The 90% illuminated, waxing gibbous Moon rises at 10:30 p.m. in Ophiuchus. About 13 degrees above the Moon, in the center of Ophiuchus, is the globular cluster M10. Three degrees above M10 is another globular cluster, M12. Globular cluster M10 was discovered by Charles Messier on May 29, 1764. It is about two-thirds the diameter of the Moon and estimated to be 14,300 light years away. M12 was discovered the night after Messier discovered M10. Unable to resolved its stars, Messier described M12 as a "nebula without stars". M12's stars can be resolved by telescopes with apertures of 8 inches or larger. Ophiuchus, the serpent bearer, is the 11th largest constellation in our night sky. This constellation is comprised of dim stars, although its brightest star, Ras Alhague, is 2.1 magnitude. Ophiuchus crosses the celestial equator, the ecliptic and the Milky Way. It is the only constellation that crosses the ecliptic but is not part of the zodiac.

The Albany Area Amateur Astronomers will be hosting public star parties at the Landis Arboretum in Esperance, NY this Friday, May 8th and Saturday, May 9th, weather permitting. Please join us as we share views through our telescopes of the many wonders of the universe.

This is the Skywatch Line for Monday and Tuesday, May fourth and fifth written by Joe Slomka.

The Sun sets at 7:59 PM; night falls at 9:51. Dawn breaks at 3:52 AM and ends with sunrise at 5:44.

The darkening sky reveals three bright planets. Venus, Mercury and Saturn present their best appearances of the year. Mercury is lowest in the West, in Taurus. It is moderately high in the sky. As seen through high-powered binoculars or telescope, it appears about 43 percent illuminated. It sets at 9:55.

Venus, also in Taurus, is the next highest planet, also in the West. At magnitude minus 4.7, it is the brightest object in the sky. In high-powered binoculars or telescopes, it is about sixty-five percent lit. It also looks larger in our instruments, since it is approaching Earth. Venus steadily climbs higher in the sky. It is about halfway between M-1, the Crab Nebula, and M-35, a star cluster in Gemini. The gap between Venus and Jupiter is progressively closing. Venus sets at 11:41 PM.

Jupiter is the highest planet of the trio. Jupiter pulls away from Cancer, and is now almost six degrees from the Beehive star cluster. Telescopic observers can witness Jupiter's moon Io begin to cross the planet during Monday's civil twilight, followed by Io's shadow at 9:47. At 10:49, Io leaves the planet's face, trailed by its shadow at 12:03 AM, Tuesday. It was highest at 7:10 PM, and now sets at about 2:20 AM.

The Moon turned "Full" on Sunday. Monday finds a slightly thinner Moon rising at 8:36 PM in Libra. Tuesday sees a still skinnier Moon rising an hour later in Ophiuchus. It remains up the rest of the night.

Saturn rises at 9:19 PM in Scorpius, appearing as an extra object in the Scorpion's head. Despite being so close to the almost Full Moon, binocular and telescopic users should have no trouble observing the giant planet. Saturn is best viewed about 2 AM, when it is at its highest. Saturn reaches Opposition this month, so it is slightly brighter and larger in our instruments. The ring system is tilted to the maximum toward Earth. Saturn also remains up the rest of the night.

Early risers can catch Neptune before the brightening Dawn washes it out. The eighth magnitude planet rises about 3:18 AM in Aquarius. At first light, it hovers about five degrees high, and requires a clear eastern horizon. If you are unsuccessful, it rises earlier later this month.

About Midnight, the constellation Scorpius lies due South, high enough for it to rise above the tree line. Its brightest star, the Lucida, is Antares. The Greek name means "Rival of Ares," the Greek version of the Roman god Mars. Antares is one of the brightest stars in the northern sky. It is one of only two bright supergiant stars, the other being Betelgeuse. Antares is truly a giant star. Its diameter is 600 million miles, beyond Jupiter's orbit. Antares lies about 600 light years away; only Betelgeuse is closer. In 1970, Antares became the first star, proven to emit radio waves.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, May 1, through Sunday, May 3, written by Alan French.

Reaching full late Sunday evening, the weekend’s night skies will be dominated by a bright, waxing gibbous Moon. The Full Moon of May is called the Full Flower Moon.

Venus continues to dominate the western skies as darkness falls. Our sister planet has been moving steadily higher in the evening sky all year, but its rate of increase has slowed considerably and there will be little change this month. Venus now sets at 11:40 pm. Through a telescope it appears two-thirds illuminated and 17 arc-seconds in diameter,

Jupiter is high in the southwestern sky at 9:00 pm. If you look at the planet at 9:00 Friday night with a telescope you’ll only see three of Jupiter’s four bright moons, Io and Ganymede to the west and Callisto farther away to the east. Europa is passing behind Jupiter from our vantage point, and will emerge from Jupiter’s shadow at 10:43 pm (appearing to Jupiter’s east).

Telescopic views Saturday night at 9:00 pm will find all four moons visible, with all to the east. In order of distance, from closest to farthest, they are Ganymede, Io, Europa, and Callisto. Ganymede is moving out from behind the planet and moving toward the east, while the other three are moving to the west and will eventually pass in front of Jupiter.

A telescope’s view on Sunday at 9:00 pm will again reveal all four of Jupiter’s bright moons. Io and Europa will be to the west and Callisto and Ganymede to the east. Callisto will be close to the east limb of Jupiter and will move in front of the planet at 11:13 pm.

Saturn, showpiece of the planets, now rises at 9:29 pm and is due south and highest at 2:19 am, when it will be just over 28 degrees above the horizon. Planets are not at their best through a telescope when so low in the sky, and the ringed-planet is not nearly as well placed from our northern latitudes as Jupiter.

Saturn’s rings, however, are still visible through any telescope magnifying 30 times and nicely seen at 60 power. The rings are now tilted 24 degrees toward Earth, so we are looking at the north face of the rings and have the best view of the planet’s northern hemisphere. If you look carefully with a telescope, you should see that the rings are divided into two rings by a dark band, known as the Cassini Division. It separates the outer A-ring from the inner B-ring, the brightest of the planet’s rings. Inside the B-ring is the subtle Crepe or C-ring, which often escapes notice.

This is the Dudley Observatory Skywatch Line for Wednesday, April 29th and Thursday, April 30th written by Louis Suarato.

The 83% illuminated, waxing gibbous Moon rises at 3:42 Wednesday afternoon. At nightfall, you'll see the Moon is between the constellation Virgo's brightest star Spica, below, and Leo's brightest star Regulus, above. To the upper right of Regulus, you'll find Jupiter in the constellation Cancer. M44, the Beehive Cluster, is 10 degrees right of Jupiter. If you have a clear west-northwestern horizon, look for Mercury about 14 degrees high. As the sky darkens, the Pleiades star cluster will appear 2.5 degrees to Mercury's upper right. Saturn rises at the head of Scorpius at 10:43 p.m.. Look over the west-northwestern horizon to see bright Venus before it sets at 11:30 p.m.. Look about 10 degrees above Venus to see open clusters in Auriga, M36, M37 and M38 (the Starfish Cluster). M36 contains about 60 stars of magnitudes between 9 and 14. Look for the brightest stars in this cluster arranged in parallel rows. M37 is 4 degrees east-southeast of M36. Look for a bright orange star at its center. M38 is 2 degrees northwest of M36. M38 contains approximately 100 stars.

Open star clusters, also known as galactic clusters, are a group of up to a few thousand stars held together by a mutual gravitational attraction. These clusters aid in the study of stellar evolution because they formed from the same molecular cloud; are all about the same distance; are approximately the same age; and have about the same chemical composition. Open star clusters are found in the spiral arms of the galaxy, unlike globular clusters, that live in the halo of the galaxy and orbit the galactic center. The other difference between open clusters and globular clusters is the age of their stars. The stars in a globular cluster can be as old as 12 to 13 billion years, while open cluster stars are as young as several million to a few billion years.

This is the Skywatch Line for Monday and Tuesday, April 27th and 28th written by Joe Slomka.

The Sun sets at 7:51 PM; night falls at 9:40. Dawn breaks at 4:06 AM and ends with the Sun rising at 5:54.

The nine-day-old Moon shines high in the southern sky. It appears about sixty-nine percent illuminated and, as the sky darkens, lies about five degrees from the bright star Regulus, in Leo. Tuesday evening finds a fatter Moon near Leo's rear leg, but in the constellation of Sextans. The Moon sets after 3 AM on both nights.

Mars is now lost in the Sun's glare. Mercury climbs higher in the western sky. In Aries, Mercury is about 11 degrees high during dusk, and about four degrees below the beautiful Pleiades star cluster. Mercury sets about 9:30 PM.

Venus is the second brightest object in the sky, at minus 4.1 magnitude. Under high powers through binoculars or telescope, it appears about the same phase as the Moon on Monday night. At nightfall, Venus appears between the horns of Taurus, the Bull. It sets at 11:30 PM.

Jupiter, third brightest, blazes high in the southwestern constellation of Cancer. Jupiter is about five-and-a-half degrees to the left of the beautiful Beehive star cluster. Telescopic observers can see several events on Tuesday night: the moon Io eclipsing its sister moon Europa between 1:59 and 2:02 AM; this causes both to dim about 1.4 magnitudes, which should be noticeable; the Great Red Spot, a giant storm on Jupiter, at 11:30 PM on Tuesday; and later see the moon Ganymede begin to cross the planet's face at 11:54. Jupiter sets at 2:47 AM.

Saturn rises at 9:49 PM and appears as an extra bright star in the head of Scorpius. It is best observed around 2:30 AM, when it is highest. The beautiful ring system is a must for any telescopic observer; under high powers, the rings break up into several segments. Saturn remains up the rest of the night.

Neptune rises in Aquarius at 3:45 AM. This distant planet makes its appearance for the first time since mid-February. Neptune is about three degrees high and obscured once the sky grows brighter. An unobstructed eastern horizon is required to see it now.

The first artificial satellite, Sputnik, was launched in 1957. Military and scientific satellites followed. However, long before Sputnik, Arthur C. Clarke, a novelist, screenwriter and physicist, had a dream. In 1947, he predicted that a satellite placed in a special orbit could act a relay for radio signals. Clarke said that, if you launched a satellite to orbit high above the Earth at the same speed as the Earth's, the satellite would appear to be stationary in the heavens. In May 1960, NASA first launched Echo, a silvered Mylar balloon, which literally bounced signals across the Atlantic. On July 10, 1962, AT&T launched Telstar, a true relay station. Telstar received and retransmitted signals between the US and Europe. Today, many such satellites crowd our skies and make worldwide television, telephone and Internet service routine. Telstar also paved the way for commercial services like Dish TV and satellite radio.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, April 24, through Sunday, April 26, written by Alan French.

Dudley Observatory and miSci will celebrate National Astronomy Day from Noon to 4:00 pm on Saturday, April 25, at the Museum of Science and Innovation (miSci) on Nott Terrace Heights in Schenectady. There will be special indoor astronomy activities, solar viewing (weather permitting), planetarium shows, and a chance to win a telescope. (Directions and admission fees can be found here or you can call miSci at 382-7890 for more information.)

If you have a location with a clear view of the west northwestern horizon and an evening where the horizon is free of clouds and haze, try looking for Mars and Mercury shortly after sunset. Start looking for the pair at 8:30 pm, when Mars will be four degrees above the horizon. On Friday Mercury will be almost three degrees above Mars. Mercury will be easiest to spot because it is brighter and is a bit higher and in fainter twilight skies. Binoculars will aid in the search if the pair is not visible by eye. Mars sets at 8:57 pm and Mercury sets at 9:15 pm Friday, 9:20 on Saturday, and 9:26 on Sunday. By Sunday night Mercury will be just less than five degrees above Mars.

Reaching first quarter at 7:55 pm Saturday, a nearly half full Moon will grace the evening sky this weekend. As darkness falls on Friday, a waxing crescent Moon will be high toward the southwest, with Jupiter well to its upper left and Caster and Pollux to its upper right. Saturday night will find a first quarter Moon higher in the sky, farther east, and closer to bright Jupiter. The pair will be about ten degrees apart. By Sunday a waxing gibbous Moon will be high in the south, with Jupiter about 7 degrees away, above and a bit right of the Moon.

This would be a great weekend to explore the Moon through a telescope. Near first quarter the terminator, marking sunrise’s march across the lunar landscape, where shadows are long and detail stands out in bold relief, is near the center of the Moon’s visible face. Any telescope will show a wealth of craters and mountains along the terminator. Explore the flatter plains for isolated craters. Look for crater walls and mountain peaks just over into the darkness that are just starting to catch the light of the rising Sun. If you watch for a while you can see more and more of the crater walls illuminated by the Sun, and sunlight creeping across the crater floor.

Through a telescope, you may find the sharpest, most pleasing view is at one of your lower powers. Using too much power can result in a dimmer, less satisfying view, and makes it harder to keep the Moon in view. Much lunar detail is also visible through steadily held binoculars.

This is the Dudley Observatory Skywatch Line for Wednesday, April 22nd and Thursday, April 23rd written by Louis Suarato.

It will be a challenge to see Mars and Mercury 1.3 degrees apart low over west-northwestern horizon 40 minutes after sunset Wednesday evening. Look over the western horizon Wednesday night to see bright Venus between the Pleiades star cluster, below and right, and the 21% illuminated, waxing crescent Moon, above and left. Say farewell to the constellation Orion, below the Moon, now setting in the west earlier each night. You'll find Jupiter, shining at magnitude -1.76, to the left of Castor and Pollux, the bright stars in Gemini. Jupiter's moon, Europa, begins its transit across the planet at 8:33 p.m., and ends at 11:26. Europa's shadow begins to transit 11:04 p.m., and ends at 1:58 a.m. Thursday.

The Lyrid Meteor Shower peaks at 8 p.m. Wednesday but is best observed between 11 p.m. and early dawn. Hourly meteor rates for this shower can range from 15 to 90. The constellation Lyra, the radiant for this shower, rises in the northeast around 11 p.m. Wednesday night. The Lyrids are derived from Comet Thatcher, which passed 31 million miles from Earth on May 5, 1861.

Saturn rises in the southeast at 10:13 p.m. in the constellation Scorpius. Look 4 degrees below Saturn for the globular cluster, M80. This globular cluster was discovered by Charles Messier in 1781. M80 is estimated to be 32,600 light-years away and contains several hundred thousand stars. Three degrees below M80 and 1.3 degrees west of the star Antares is the globular cluster M4. At the distance of approximately 7,200 light-years, M4 is one of the closest globular clusters. Hubble photographs from 1995 revealed that M4 contains some of the oldest stars in the universe. Some stars in M4 are estimated to be 13 billion years old.

This is the Skywatch Line for Monday and Tuesday, April 20th and 21st written by Joe Slomka.

The Sun sets at 7:43 PM; night falls at 9:28. Dawn breaks at 4:20 AM and ends with the Sun rising at 6:04.

The southwestern sky presents an interesting arrangement of heavenly bodies. Monday's two-day-old Moon occupies Taurus, the Bull. It appears between the Hyades and Pleiades star clusters, in addition to nearby stars: red Aldebaran, the Bull's Eye, and Sirius, the brightest star in the sky. Venus appears higher above the Moon; it is second brightest only by one-tenth of a magnitude – too close for most people to distinguish. On Tuesday, a more gibbous Moon snuggles up next to Venus, and clearly outshines the planet. Telescopes or binoculars reveal that the Moon is only six percent illuminated on Monday, and thirteen percent on Tuesday. Compare the Moon to Venus, which also exhibits phases, and is about 71 percent lit. These two nights present an opportunity for first-time astro-photographers. All set after 11 PM.

Dusk also contains Mars and Mercury. They lie low in the western sky. Mars is about seven degrees high, while Mercury is about five-and-a-half degrees. However, Mercury is much brighter than Mars, and may serve as a guide to the Red Planet. Both should fit within a binocular or telescope view; naked eye viewers will have difficulty finding them in the sunset glare. Both set by 9 PM.

Jupiter, in Cancer, is at its highest in the southwestern sky at 8 PM. Its Galilean Moons experience several telescopic events these nights. Monday night, Io eclipses Europa between 11:44 and 11:47 PM. Tuesday night, Ganymede begins its march across Jupiter at 8 PM; it exits Jupiter at 11:36 PM. Ganymede's shadow begins its own trek across Jupiter at 1:01 AM on Wednesday and continues until Jupiter sets at 3:14 AM.

Comet Lovejoy continues to darken; it is now reported at seventh magnitude. The comet is still in Cassiopeia and about three-and-a-half degrees west of the star Omega, and ten degrees above the star Epsilon. Cassiopeia does not set, but is quite close to sunset glare.

Saturn rises in Scorpius at about 10:19 PM and is highest at about 3:15 AM. It appears as an extra bright star in the Scorpion's head.

Observers who stay up after midnight Tuesday night may see meteors streaking from the East. This is the annual Lyrid meteor shower, which peaks the night of the 22nd/23rd. Like most meteor showers, the Lyrids are litter left over from passing comets; as these specks of dust enter our atmosphere, they burn up in a fiery trail. This meteor shower has been continuously observed for over 2600 years. The shower is linked to Comet Thatcher and appears to originate near the bright star Vega in the constellation Lyra. Typically, between ten and twenty meteors are seen per hour. However, there have been sporadic cases of the shower rate exceeding three hundred per hour. The most recent outburst occurred in 1982, with about ninety per hour.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, April 17, through Sunday, April 19, written by Alan French.

This is a weekend amateur astronomers throughout the Northeast look forward to – the annual Northeast Astronomy Forum (NEAF) at Rockland Community College in Suffern, New York. This is the world’s largest trade show of telescopes and accessories, and it’s only a two to three hour drive from the Capital District region. In addition to exhibits by more than 100 vendors of, there are lectures, programs for beginners, and special events for children. Weather permitting; there is also a solar star party, where some of the finest safe solar telescopes provide fantastic views of the Sun, in white light and the red light of glowing hydrogen.

Event hours are 8:30 am to 6:00 pm, Saturday, April 18, and 10:30 am to 5:00 pm, Sunday, April 19. Admission is $25 for one day or $40 for both days. For full details visit the NEAF web site.

Locally, Friday night features the first Dudley Observatory of the year at the Octagon Barn (588 Middle Road, Delanson, NY 12053). At 7:30 pm Julie Muffler, Flight Director of the upcoming Challenger Learning Center at miSci, will talk about the center and its activities. Following her talk, if the skies are clear, there will be a public star party, with telescopes set up to provide guests with views of the night sky. Jupiter will be well placed for viewing. The program is free, although a modest $5 donation is always appreciated.

Also on Friday night, weather permitting, is a public star party at the Deerfield Pavilion in Grafton Lakes State Park beginning at 8:15 pm. This event is canceled if the skies are mostly cloud. If in doubt, or for more information, call Bernard at 658-9144 or Ray at 658-3138.

There are two fine passes of the International Space Station (ISS) over our area this weekend. The one Saturday night passes almost directly overhead and moves into the Earth’s shadow and fades from view while still high in the sky. Sunday’s pass is earlier and a bit lower. Times will be given in hours, minutes, and seconds. They are for Schenectady, but should be close enough for anyone in the Capital District region.

Saturday night the ISS will move up from the west northwestern horizon at 9:22 pm. It will be highest just after 9:25 pm when it will be 80 degrees above the south southwestern horizon – appearing essentially overhead. It will move into the Earth’s shadow and fade from view at 9:25:32 when 64 degrees above the south southeastern horizon. You can see its path across the sky here. (Remember that star charts should be held with the direction you are looking at the bottom.)



On Sunday night the ISS will appear in the northwest at 8:28 pm, will be highest at 8:31:17 when 56 degrees above the north northeastern horizon, and will move into the Earth’s shadow seconds before 8:34 when only 14 degrees above the east southeastern horizon. Its path across the sky can be seen here.

This is the Dudley Observatory Skywatch Line for Wednesday, April 15th and Thursday, April 16th written by Louis Suarato.

Double stars can be two stars that visually seem close, but are actually very far apart, and are in the same line of sight. Double stars can also be binary stars that are gravitationally bound and orbit each other. Mizar, the second star from the end of the Big Dipper's handle, was one of the first double stars to be discovered. Mizar, along with Alcor, form a binary star system. This double star was discovered by Benedetto Castelli in 1617. April 15 is the birth date of astronomer Friedrich von Struve. Born in 1793, von Struve is known for his observations of double stars. Equipped with an 9.5 inch refracting telescope, von Struve discovered over 2,000 double stars after becoming the Director of the Dorpat Observatory in Estonia in 1817. Notable double stars include Albireo, the star at the head of Cygnus the Swan. Albireo is a binary system consisting of a gold star and a blue star orbiting a central mass. Follow the Big Dipper's arc to Arturus, the brightest star in the constellation to find the double star formed by Kappa Boötis and Iota Boötis. Look for these double stars at the far north of this constellation. Kappa Boötis consists of stars of magnitude 4.6 and 6.6. Look for the blue companion within this double star.

A moonless Wednesday evening offers the opportunity for optimal skywatching. Start your evening viewing two bright planets. Venus will be over the western horizon after sunset, a few degrees left of the Pleiades star cluster. The face of Venus is now 72% illuminated. Jupiter will be high over the southern horizon in the constellation Cancer at twilight. Jupiter's moon Europa transits the planet between 6:01 p.m. and 8:54 p.m.. Europa's shadow transits between 8:28 p.m. and 11:21 p.m.. The constellation Boötis will be low over the eastern horizon after sunset, and will be higher later in the night for you to search for the double stars mentioned earlier. Saturn rises in Scorpius at 10:42 p.m., and will be low over the southwestern horizon in the pre-dawn sky. The 8% illuminated, waning crescent Moon rises at 5 a.m. Thursday morning. The Moon reaches perigee, its closest approach to Earth during this lunar cycle, on Thursday at 11:48 p.m. at a distance of 224,329 miles.

The Dudley Observatory invites you to join them for an Octagonal Barn Lecture and Star Party beginning at 7 p.m. Friday, April 17th. The barn is located at 588 Middle Road, Delanson, NY.

This is the Skywatch Line for Monday and Tuesday, April 13th and 14th written by Joe Slomka.

The Sun sets at 7:35 PM; night falls at 9:17. Dawn breaks at 4:34 AM and ends with sunrise at 6:16.

The darkening sky reveals three planets. Venus, in Taurus, is the first to appear, and is also the brightest. It is moderately high in the western sky. These nights, it lies between the Hyades star cluster, which forms the face of Taurus, and the Pleiades star cluster, which appears above the Bull's shoulder. Both are great binocular objects. Under high power, Venus appears about three-quarters illuminated and growing in apparent size daily. Mars, in Aries, glows at first magnitude about 23 degrees to Venus' lower right. Mars is very close to the sunset glare and may require binoculars or telescope to locate it. This may be your last chance to see Mars before it is hidden by the Sun. Mars sets at 8:57 PM, Venus at 11:02.

Jupiter, in Cancer, blazes high in the South. It is visibly brighter than the star Sirius, which is half as high in the constellation of Canis Major – The Big Dog. Jupiter is now moving away from Cancer and returns to eastward movement. Tuesday night, the moon Ganymede begins to cast its shadow on its planet at 9 PM; the shadow exits at 12:38 AM, Wednesday. Jupiter is still about five degrees from the binocular Beehive Star Cluster, also in Cancer. Jupiter sets at 3:41 AM.

Comet Lovejoy occupies "W"-shaped Cassiopeia and is also still visible in small to medium telescopes and binoculars. The comet is slowly dimming; recent reports have it at magnitude 6.7. It is about three degrees to the right of stars 50 Cassiopeiae and seven degrees below Epsilon.

Saturn rises within Scorpius at 10:44 PM and remains up the rest of the night. The zero magnitude planet appears as an extra star in the Scorpion's head. The rings are tilted to us and make Saturn brighter than it would be without the rings.

The waning Moon rises at 3:40 AM in Capricornus on Tuesday, and 4:18 AM on Wednesday. It appears about twenty percent illuminated and remains up the rest of the day.

Hydra, the Water Snake, wends its way southward beneath Cancer and Leo. Two constellations ride on its back, Corvus and Crater. Corvus is known as either a Raven or a Crow, due to conflicting legends. One story depicts a snow-white Raven as Apollo's messenger. When the Raven gives Apollo the especially bad news that his wife was unfaithful, the angry god changed the Raven's feathers black (the color of contemporary ravens) and banished him to the sky. The other myth sees the Crow again as Apollo's messenger. When the god asks for a cup (Crater) of water, the Crow departs, but is distracted by a fig tree, full of ripening fruit. The crow took too long, returning with a water snake (Hydra) in his claws. The fuming deity exiled the bird, the snake and the cup to the night sky.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, April 10, through Sunday, April 12, written by Alan French.

The Moon reaches last quarter late Saturday so it rises during the early morning hours, leaving the evening sky moonless and dark.

Venus continues to dominate the western sky as darkness falls. It is close to the Pleiades, an attractive star cluster known to many as The Seven Sisters. Look for the small cluster, shaped roughly like a very small dipper, to the right of Venus. It will be easiest to spot after the glow of twilight has faded. Venus doesn’t set until just before 11:00 pm, and the sky will be completely dark by 9:15 pm. The pair will be just under three degrees apart and will be a lovely sight in binoculars.

Traveling on its inner, faster orbit the “evening star” has slowly been catching up with Earth. As it does so, the view through a telescope changes. It is moving closer to us so it grows larger, and more of the daylight side of the planet is facing away from us, so we see less and less of the sunlit side.

Venus now appears as a small gibbous disc, 14 arc seconds across, and is 77% illuminated. By the end of July Venus will appear 52 arc-second across and only 7% illuminated, appearing as a slender crescent though a telescope.

Weather permitting the Albany Area Amateur Astronomers will take advantage of the dark skies by hosting two public star parties at Landis Arboretum in Esperance this weekend. At star parties club members set up a variety of telescopes and show guests some of the celestial showpieces. Star parties are canceled if the skies are mostly cloudy. Due to the changeable weather here, and current wet conditions, you should call 374-8460 to verify that the star party is being held. Call after 6 pm.

The star parties will be held at 8:30 pm on Friday, April 10, and Saturday, April 11. They are usually held in the Meeting House field, which is on the right about 100 feet after you pass the Arboretum’s farmhouse, also on your right, on Lape Road. On rare occasions star parties are moved to the farmhouse area, so watch for a sign as you pass the farmhouse and main parking area. You can find directions at the Landis Website.

Jupiter is well placed for evening viewing right now. On Friday night Jupiter’s moons Io and Ganymede will be to the west of the planet, while Europa and Callisto will be to its east. On Saturday Europa, Ganymede, and Callisto will be to the east, and Io will be passing in front of the planet, followed by its shadow. The transit of Io starts just before the star party. The shadow transit, which is easier to see and appears as a black dot on Jupiter’s cloud tops, begins at 9:33 pm.

Guests of all ages are welcome at star parties. There is no fee, although we encourage guests to make a donation to our fine host, the Landis Arboretum.

This is the Dudley Observatory Skywatch Line for Wednesday, April 8th and Thursday, April 9th written by Louis Suarato.

Venus is now 75% illuminated and shines at a magnitude of -3.53 Venus will be visible over the western horizon after sunset. Look 3 degrees above Venus, when the sky is dark, for the Pleiades star cluster. Around 8:30 p.m., you'll be able to locate Jupiter about 65 degrees above the southern horizon in the constellation Cancer. Wednesday night, Jupiter's moons Ganymede, Europa and Io will be to one side of the planet, while Callisto will be occulted until after midnight, when it reappears on the other side. At 11:51 p.m., Europa occults Io. Less than two hours later, Europa eclipses Io. Saturn rises in Scorpius after 11 p.m. followed by the 80% illuminated, waning gibbous Moon a half hour later. Look over the pre-dawn southern horizon to see a triangle formed by the Moon, Saturn and Scorpius' brightest star, Antares. Mercury reaches superior conjunction as it passes behind the Sun Thursday night, and will reappear in the evening sky in ten days.

With the constellations Leo and Ursa Major high in the sky during April, here are a few suggestions for Messier objects viewable by binoculars and telescopes. M65, also known as the Leo Triplet, consists of spiral galaxies M65, M66 and NGC 3628. This small group of galaxies is approximately 35 million light-years away. You'll be able to locate these galaxies two degrees below the star Chertan in Leo. Chertan is the star between Leo's brightest star, Regulus, and Denebola, at the tail of the lion. M97, also known as the Owl Nebula, is a planetary nebula in Ursa Major. A planetary nebula forms as the result of giant red stars at the end of their stellar lives. The nebula is formed by expanding, glowing ionized gas. The term "planetary" nebula was coined by William Herschel, who thought these objects resembled planets. M97 is in the same field of view as the galaxy M108. Both are located in Ursa Major. Look for M97 and M108 one degree east from the star Merak, the bottom star at the front of the Big Dipper's bucket.

The Albany Area Amateur Astronomers will be hosting star parties this Friday and Saturday at the Landis Arboretum in Esperance, NY. Weather permitting, amateur astronomers will offer telescopic views of planets, nebulae, galaxies, double stars, and star clusters. Directions to the arboretum can be found on http://www.dudleyobservatory.org/AAAA/Directions.html

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This is the Dudley Observatory Skywatch Line for Monday and Tuesday, April Sixth and Seventh written by Joe Slomka.

The Sun sets at 7:27 PM; night falls at 9:06. Dawn breaks at 4:48 AM and ends with sunrise at 6:27.

The evening sky displays three bright objects, a star and three planets. The star is Sirius, the Dog Star, moderately high in the South. Venus is far brighter and higher, but in the southwest. High powered binoculars and telescopes show Venus as growing in size, but displaying a thinner crescent. Venus sets about three hours after sunset; Monday night, it sets at 10:46.

Mars is much dimmer, and about twenty degrees to Venus’ lower right. The Red Planet is getting close to the twilight glare. Now is the time to get last looks at Mars.

Mars sets at 8:58.

Jupiter also illuminates the evening sky. It appears above Sirius, and is also much brighter. After nightfall, Jupiter is about five degrees to the left of the Beehive star cluster, also called M 44. Both objects should fit within the same binocular view. At 8:27 PM on Monday, telescopic observers can see the Jovian moon Europa disappear into the giant planet’s shadow; Europa reappears at 1:37 AM, Tuesday. They can also see the Great Red Spot, a giant storm, centered on Jupiter at 9:15 PM on Tuesday.

Nighttime permits views of Comet Lovejoy. The comet is still glowing at sixth magnitude, placing it within binocular and telescopic inspection. It currently lies about six degrees from 50 Cassiopeiae, and five degrees from Epsilon. The comet is still circumpolar, which means it does not set. The seventeen-day-old Moon rises at 9:44 Monday night and is highest at 3:02 AM, Tuesday. It lies in Scorpius. Saturn is one of the few objects to withstand the Moon’s glare. The Moon sets during daytime. Wednesday’s dawn sees the Moon only two degrees from Saturn. Saturn rises about 11 PM and appears as an extra bright star in the head of Scorpius. Its rings are tilted at about 24 degrees, presenting a great spectacle for first-time viewers.

As night falls, the unmistakable shape of Leo, the Lion, dominates the evening sky. Leo is one of those constellations that look like its namesake. If one looks past Denebola, the Lion’s Tail, one sees a faint hazy cloud. Binoculars show it to be a galactic star cluster. This cluster is called Coma Berenices. Unlike most constellations, Berenice was not a mythical figure. She was married to Ptolemy III of Egypt. When her brother-in-law involved the Pharaoh in a war, Berenice, like all wives, worried about her husband in battle. She vowed to Aphrodite that she would donate a lock of her hair if Ptolemy arrived home safely. He did; and she fulfilled her promise. One night the royal couple inquired of the court priest-astrologer what happened to her donation. He replied by pointing to the hazy cloud in the sky and said the gods accepted her sacrifice. Berenice is famous for another reason; she is Cleopatra’s grandmother. The modern Libyan city of Benghazi bears a modified version of her name.


This is Dudley Observatory’s Skywatch Line for Friday, April 3, through Sunday, April 5, written by Alan French.

As you may have heard, there is a total lunar eclipse on Saturday morning. Alas, we do not have very good seats and will only get to see the very beginning. As you move west more and more of the eclipse will be visible. A little more than half the nation gets to see totality, but only the very western edge of the country gets to see the end of totality.

The Earth casts a shadow into space. The shadow has two parts, a bright, outer penumbra, where our Earth only blocks part of the Sun, and a darker, inner umbra, where out planet fully blocks direct sunlight. The umbra is not completely dark – our atmosphere refracts or bends some sunlight into the umbra. (From the Moon during a total lunar eclipse, you’d see the sunrises and sunsets all around edge of the Earth. It is this light that colors the Moon during the eclipse, often making the Moon appear reddish.)

The penumbral phase, when the Moon is moving into the brighter outer part of the Earth’s shadow, is neither obvious nor impressive. The penumbral shadow is not visible on the Moon until the lunar orb is fairly well into the shadow. From here we will see the Moon move through the penumbra and the first 15 minutes or so of the partial umbral phase. The Moon, 16 degrees above the west southwestern horizon, will enter the penumbra at 5:00 am on Saturday morning, but the subtle shading will probably not be visible until about 5:35, when the Moon is deeper into the shadow.

For the start of the partial umbral phase, beginning at 6:15 am, you’ll need a clear view to the west. At 6:15 the Moon will be just over three degrees above the horizon. Moonset for Schenectady is at 6:38 am, so you won’t have long to see the Moon partially in the umbral shadow. We have a choice seat for the September 28 total lunar eclipse.

If you would like to enjoy the entire eclipse, Griffith Observatory will host a live webcast from 5:00 am until 9:30 am EDT.

The International Space Station, which has now returned to our evenings skies. There is a lovely and interesting pass on Saturday night, where the ISS will move into the Earth’s shadow and fade from view while still high in the sky. (Times will be given in hours, minutes, and seconds.)

The ISS will first appear at 8:58:29 pm coming up from the southwestern horizon. It will be highest at 9:01:44 when 79 degrees above the southeastern horizon (appearing essentially overhead), and will move into the Earth’s shadow and fade from view at (9:02:26 when 52 degrees above the east northeastern horizon. The space stations path will bring it up past Orion, between Gemini and Jupiter, and it will fade from view while traveling below the handle of the Big Dipper.

This is the Dudley Observatory Skywatch Line for Wednesday, April 1st and Thursday, April 2nd written by Louis Suarato.

Wednesday, after sunset, look for Mars to appear low over the western horizon approximately 18 degrees below Venus. Above Venus, in the constellation Taurus, are the Pleiades. To the left of Taurus is the constellation Orion. This winter constellation is still visible, but sets earlier in the west with each passing night. Above Orion is Gemini, with its two brightest stars, Castor and Pollux. Look to the south of Gemini for Jupiter, the third brightest celestial object in tonight's sky after the Moon and Venus. To the east of Jupiter is Leo, one of the most predominant Spring constellations, with its brightest star, Regulus, and lion's mane, formed by the Sickle asterism. You'll find the 94% illuminated, waxing gibbous Moon below Leo. On Wednesday, the Moon reaches lunar apogee at 252,284 miles, its furthest distance from Earth during this lunar cycle. You'll have to wait until after 11:30 p.m. to see Saturn. Saturn will be higher in the pre-dawn sky, above Scorpius' brightest star, Antares. Saturn's rings are now tilted at 25 degrees toward Earth. Mercury, currently traveling behind the Sun, should reappear around April 19th, and will be visible to the naked eye after sunset, low over the west-northwest horizon.

By 9 a.m., the constellation Ursa Major fills the northern sky from an altitude of 40 to 80 degrees. Within this constellation, the Big Dipper asterism can be seen even under light polluted skies. Binoculars or a small telescope will reveal that the star at the bend of the Big Dipper's handle are actually two stars, Mizar and Alcor. Some may be able to see the two stars with the naked eye under the right conditions. Mizar, the brighter of the two, is a second magnitude star, and Alcor is a fourth magnitude star, east of Mizar. A telescopic view of Mizar will display that this star itself is actually a double star. Mizar was the first binary star discovered using a telescope.

This is the Skywatch Line for Monday and Tuesday, March 30th and 31st written by Joe Slomka.

The Sun sets at 7:19 PM; night falls at 8:56. Dawn begins at 5:03 AM and ends with sunrise at 6:40.
The eleven-day-old Moon, in Leo, brightens, at magnitude minus 4, the darkening sky. It is high in the South. Tuesday, it lies close to Regulus, the brightest star in Leo. It sets around 5 AM.

Venus is second brightest and resides in Aries. Venus appears about three-quarters illuminated. Venus grows brighter but thinner in our binoculars and telescopes during the month. Mars shares Aries with Venus, and lies low in the southwest. It appears as a nearly full rust-colored ball. Mars sets at 8:58 PM, Venus at 10:29.

Jupiter, in Cancer, lies close to the Moon on Monday night. Tuesday night, it appears near the Beehive star cluster, also in Cancer. Despite the Moon's brilliance, Jupiter's four Galilean moons are observable. At 11:02PM on Monday, Europa's shadow exits Jupiter's face; at 11:14 PM on Tuesday, Callisto's shadow begins its travels across Jupiter. Jupiter is highest at about 9:24 PM, and sets at 4:36 AM.

Comet Lovejoy still resides in Cassiopeia. The comet is now slowly fading; recent reports place it at about sixth magnitude. People with good vision probably can see it with the naked eye in dark, rural areas. It is certainly visible in binoculars and telescopes. The comet lies within five degrees of the star Delta and M 103, both in Cassiopeia, and does not set.

Saturn rises before Midnight in Scorpius. It appears as an extra bright star in the Scorpion's head. Though easily seen with the naked eye, one needs high-powered binoculars or almost any size telescope to appreciate its ring system.

For the last few weeks, astronomers have been getting up in the pre-dawn hours to see a "new star," a nova. This star is located in teapot-shaped Sagittarius. The star is located just below where the teapot's top meets the rim of the teapot's base and in the middle between the handle and the spout. It was originally noted at fourth magnitude, but now is fading. Recent observer reports estimate its brightness at about magnitude 5.5, which means it is visible in dark, rural skies.

Novae, the plural of "nova," are fairly common events. A white dwarf star orbits a larger star. The heavier dwarf sucks part of its companion's atmosphere onto itself. A hydrogen layer develops on the dwarf, until it is so dense that the layer self detonates into a gigantic hydrogen-bomb type explosion. These novae suddenly brighten in our skies and then slowly fade. Once the explosion settles down, the dwarf resumes stealing hydrogen from its companion. It will experience another nova; but, depending on the rate it accumulates hydrogen, the white dwarf may explode after a few years or after a thousand years. This one started off as magnitude 4.3 and faded to 5.5 within 24 hours. This is the brightest nova in Sagittarius since 1898.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, March 27, through Sunday, March 29, written by Alan French.


Venus continues to grace the western sky with its unrivaled brilliance after darkness falls. Indeed it is bright enough to spot easily just after sunset, and can even be seen in broad daylight – if you know where to look. It’s easiest to spot when it happens to be near the Moon, but that happens infrequently, and often doesn’t coincide with clear skies. The task is simplified at other times by looking for Venus when it is due south and highest.
With Venus is in the evening sky, a useful tactic is to find a viewing location to the east of a building, where you will be in shade while searching for our sister planet. This weekend Venus is due south within at 3:16 pm, when it will be 64 degrees above the southern horizon. (The odds are that it will seem higher, and closer to directly overhead than you expect.) It may take some time to spot it by eye, but once you’ve sighted Venus, you’ll be surprised how easy it is to see against the blue sky.
There are two reasons Venus is hard to spot. First, your eye has nothing to focus on when looking at the blue sky. Indeed, a few clouds or a contrail close by sometimes make it easier to spot Venus. Second, the best visual acuity of your eye is restricted to a small area near the center of your view. If you are not looking almost directly at it, you’ll probably miss it.
If you can’t find Venus by eye, try looking with binoculars. Make absolutely sure your viewing location, in the shade to the east of a building, will not allow you to accidentally look at the Sun. (With the Sun moving westward, it can not move into your view if you are in such a location. This is not true when Venus is in the morning sky and to the west of the Sun.) Carefully focus your binoculars on something way in the distance, or a passing jet or contrail. Then scan upward from the southern horizon. Once you spot it, try again by eye. It really helps to know where it is, and I often use a distant tree as a landmark, noting in binoculars which Venus lies directly above.
The Moon was at first quarter very early on Friday, so a waxing gibbous Moon will dominate the weekend’s night skies. The days around first quarter are ideal times to observe the Moon through steadily held binoculars or a telescope. Detail along the terminator, the line between the sunlit portion and darkness, stands out in bold relief because shadows are longest there. As we move from new to full the terminator is the line of sunrise marching across the Moon.
On Sunday night the Moon will be near Jupiter, high toward the south at 9:00 pm. A telescope will reveal Jupiter’s own moons Io, Ganymede, and Callisto stretched out to the planet’s east and Europa to its west.

This is the Dudley Observatory Skywatch Line for Wednesday, March 25th and Thursday, March 26th written by Louis Suarato.

After the Sun and Moon, Venus is the third brightest celestial object in the sky. Venus' brightness is attributed to its proximity to Earth. It is the next closest planet but there is another factor causing Venus' brightness. The term albedo refers to the comparison between the amount of light absorbed versus the amount of light reflected. Venus reflects 70% of the light hitting the planet, the second highest albedo in our solar system. Venus' cloud cover is highly reflective, causing the albedo of about 7. The most reflective body in our solar system is Saturn's moon Enceladus, with an albedo of 9, indicating it reflects 90% of sunlight from its icy surface. You can't miss Venus over the western horizon after sunset. You still may be able to see Mars below Venus, close to the horizon and becoming lost in the glow of twilight. Above Venus is the 26% illuminated waxing crescent Moon just below the Hyades open star cluster and Taurus' brightest star, Aldebaran. You'll find the Pleiades star cluster to the Moon's lower right.

The end of twilight reveals Jupiter about 50 degrees over the southeastern horizon. Saturn rises minutes after midnight in the constellation Scorpius. It was 360 years ago on March 25, 1655, that Christiaan Huygens discovered Saturn's largest moon, Titan. Titan is the second largest moon after Jupiter's Ganymede. Titan's diameter is larger than the planet Mercury but 50% larger than Earth's moon. Titan's atmosphere is 95% nitrogen and 5% methane. Since methane is diminished by sunlight, scientists believe there may be other forces replenishing Titan's most plentiful gas, such as volcanic activity.

There will be a bright, 3rd magnitude, International Space Station pass over our region beginning at 5:55 a.m. Thursday. Look to the northwest horizon and follow the ISS as it passes above the Big Dipper, below Cassiopeia and Pegasus, and continues toward the eastern horizon.

This is the Skywatch Line for Monday and Tuesday, March 23rd and 24th written by Joe Slomka.

The Sun sets at 7:11 PM; night falls at 8:46. Dawn breaks at 5:16 AM and ends with sunrise at 6:52.

The four-day-old Moon brightens the darkening sky; it is moderately high in southwest, appearing in Taurus. The thin crescent Moon sets at 11:19 PM on Monday, and 12:22 AM on Wednesday.

Venus, the second brightest object, lies to the Moon's lower right, and appears about eighty percent illuminated. It sets an hour before the Moon. Notice that, this month, Venus grows larger in our telescopes, but progressively less lit.

First magnitude Mars shines about fourteen degrees below Venus. Its distinctive rust color easily identifies it. Mars sets about 9 PM. Sixth magnitude Uranus is about nine degrees below Mars. Spotting it in the darkening sky will be difficult due to its low altitude and brightness. Uranus sets at 8:13 PM. Notice that these planets form a straight line, demonstrating the Ecliptic – the path of Sun, Moon, and planets across our sky.

Jupiter has already risen in the East and is highest, due South, at 9:53 PM. Jupiter sets at 5:05 AM.

Comet Lovejoy is visible in Cassiopeia at nightfall. Although Lovejoy is streaking away from Earth, it is still at 5.8 magnitude, within binocular and small telescope view. The comet also lies about three degrees from star clusters M103 and NGC 457.

Saturn rises shortly after Midnight, appearing as an extra bright star in Scorpius. Even small telescopes reveal its glorious ring system. Larger telescopes display the various gaps within the rings and some of Saturn's sixty-two moons. The easiest of these is Titan, Saturn's largest satellite. In fact, Titan is larger than planet Mercury and is the only moon to have an atmosphere. Titan's surface is hidden by its thick atmosphere, which consists of nitrogen and hydrocarbons. This combination gives the otherwise frigid satellite a greenhouse effect, warming it to minus 292 degrees Fahrenheit. In 2005, the Huygens space probe landed on Titan, and revealed rivers and lakes of liquid methane.

Wednesday is the 360th anniversary of Christian Huygens' discovery of the Saturnian moon Titan. Christian Huygens was a Seventeenth Century scientific giant. He made discoveries in the fields of: astronomy, game theory and horology (time). He improved spherical lenses; today, astronomers still use Huygens eyepieces. He observed the 1661 transit of Mercury across the Sun, worked on laws of gravity and light, invented the first projector, the first pendulum clock and improved the pocket watch. While Galileo first observed Saturn through a telescope, he was confused by the rings, which he called "ears." Huygens, observing Saturn with a fifty-power telescope, was the first to call them a "ring;" later astronomers discovered gaps in the ring. Huygens even published a book on extra-terrestrial life.

For his many accomplishments, Huygens was honored. The Cassini space probe to Saturn carried the Huygens lander. Asteroid 2801 was named for him, as were a crater on Mars and a mountain on the Moon.

Clear Skies

This is Dudley Observatory’s Skywatch Line for Friday, March 20, through Sunday, March 22, written by Alan French.

The Moon is new early Friday. At new the Moon passes between our Earth and the Sun, but it usually passes above or below the Sun. When the Moon passes in front of the Sun, we have a solar eclipse. There will be a solar eclipse on March 20, but it will not be visible here. It will be total along a path in the North Atlantic. The path will cross some remote islands, including the archipelago of Svalbard, halfway from Norway to the North Pole. Partial phases will be visible in Iceland, Greenland, Europe, North Africa, western Asia, and East Asia. In spite of its remote location, there will be a few “eclipse chasers” who will go and see it.

Residents of the United States will have a fine chance to see a total solar eclipse on August 21, 2017, when the path of totality will sweep across the country from northern Oregon through central South Carolina. From here it will be a partial eclipse, but it is well worth planning a trip to somewhere along the path of totality. A total solar eclipse can not be properly conveyed through photos or video and really should be experienced in person. After 2017, the next chance to see a total eclipse in the United States will be on April 8, 2024. Its path will take it through western and northern New York.

A slender crescent Moon returns to the early evening sky on Saturday night, with the young Moon near Mars. Look for the pair a little south of due west around 7:15 pm, when reddish Mars will be a degree and a half to the upper right of the young Moon. On Sunday night the slightly fatter Moon will be near brilliant Venus. Just over three degrees will separate the pair. By 7:30 pm the darkening sky should make them a lovely sight. With the right foreground they would make a nice photograph.

If you look high in the west northwest around 8:00 pm you’ll easily spot bright Capella, the luminary of the constellation Auriga, the Charioteer. If you have the right star, you’ll see a small triangle of stars to its lower left. They are known as The Kids, or baby goats.

Capella is the sixth brightest star in the night sky and lies 42 light-years away. It is a famous double star. Each star has about the same surface temperature as our Sun, but there the similarity ends. One is 50 times the Sun’s luminosity and the other 80 times, and both are about ten times the diameter of the Sun. They are only about 60 million miles apart, less than the 93 millions miles between our Earth and the Sun, and can not be seen separately in even the best telescopes.

The pattern that outlines the stars of Auriga is easy to spot. Look for a rough pentagon of stars, including Capella, with the remaining stars above and left of Capella. Capella is the northernmost first magnitude star, lying about 44 degrees from Polaris.

This is the Dudley Observatory Skywatch Line for Wednesday, March 18th and Thursday, March 19th written by Louis Suarato.

As Mars draws closer to the western horizon each evening after sunset, Jupiter rises higher in the southeast. Mars begins to appear after 7:30 p.m. below the much brighter Venus. Shining at a magnitude of -3.45, Venus is now 82% illuminated. Look for the Pleiades star cluster about 30 degrees above Venus, and 25 degrees below Auriga's brightest star, Capella. At magnitude 0.05, Capella is the sixth brightest star in our night sky. Capella is also the brightest star of the same spectral type as our Sun. At a distance of 42 light-years, Capella appears as a yellow or golden star. A telescopic view reveals Capella to be a binary star consisting of two golden stars, both two and a half more massive than our Sun.

Look for Jupiter about 60 degrees above the southeastern horizon around 9 pm. All four Galilean moons will be located to one side at that time, with Callisto farthest from the planet, then Ganymede, Europa and Io inward. NASA has recently confirmed that Ganymede has a saltwater ocean beneath its icy surface. Scientists have stated that Ganymede, the largest moon in our solar system, may bear more liquid than all of the water on Earth. NASA’s Science Mission Directorate, John Grunseld, said, “A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”

Take advantage of the moonless nights to search for some galaxies. To the lower left of Jupiter is the constellation Leo's brightest star, Regulus. Approximately 8 degrees to the lower left of Regulus, are a group of galaxies known as the Leo I Group. This group consists of the bright spiral galaxies M95 and M96, and the elliptical galaxy, M105. M105 is the closest elliptical galaxy to our solar system.

Friday morning, the New Moon occurs at 5:36 a.m. EDT, 9 hours after lunar perigee. Higher, and lower than normal tides can be expected. This weekend, the Albany Area Amateur Astronomers kick off their 2015 star parties. Weather permitting, there will be star parties at the Landis Arboretum this Friday and Saturday nights. Directions to the arboretum can be found at http://www.dudleyobservatory.org/AAAA/Directions.html.

This is Dudley Observatory’s Skywatch Line for Monday, March 16, through Tuesday, March 17, written by Alan French.

On March 16, 1926, Robert Goddard launched the first liquid fueled rocket at Auburn, Massachusetts. He did extensive research on rockets and their potential for space flight. It was only after the dawn of the Space Age that he became recognized as the father of modern rocketry.

The Moon is approaching new so a waning crescent will grace the morning sky before sunrise. As morning twilight begins on Tuesday, look for a slender crescent very low in the east southeast. At 6:15 am the Moon will be just over 4 degrees above the horizon. On Wednesday morning the Moon rises in the east only 26 minutes before sunrise and will be very difficult to spot against the bright twilight skies. The Moon reaches new early Friday.

Venus and Jupiter continue to be the brightest “stars”of the evening sky, with Venus well up in the western sky as darkness falls. Jupiter can be found high in the east southeast just after sunset, and is due south, highest, and best seen through a telescope at a convenient 10:19 pm.

With the gas giant 65 degrees above the horizon, we are viewing through less of Earth’s atmosphere and detail in the cloud tops is generally easier to see. Any telescope magnifying 60 times or so will show two dark bands, the North and South Equatorial Belts, crossing the planet to either side of the bright Equatorial Zone. A careful and patient observer, waiting for those moments of steadier views, may glimpse considerable detail on the planet.

The four largest and brightest Jovian moons are visible through any telescope, and may even be spotted through steadily supported binoculars when they are not too close to the planet and thus out of the planet’s glare. On Monday night at 10:00 pm Ganymede and Europa will be to the east of Jupiter and Io and Callisto to the west, with Callisto about three times as far away as Io. They appear as bright stars through a telescope.

On Tuesday Io and Europa will be to the east and Ganymede and Callisto to the west. If unsure ofdirections in your telescope, move it toward the west. Objects will move toward the east in your field of view.

You’re invited to a meeting of the Albany Area Amateur Astronomers at 7:30 pm this coming Thursday, March 19, at miSci. The program will be “Winter Star Party,” a look at an annual astronomy convention held each year in the Florida Keys (and a good excuse to flee to cold northern latitudes!). Meetings are free and open to all.

This is Dudley Observatory’s Skywatch Line for Friday, March 13, through Sunday, March 15, written by Alan French.

Reaching last quarter early Friday afternoon, a waning crescent Moon will rise well after midnight over the weekend. Moonrise is at 2:41 am Saturday, 3:33 am Sunday, and 4:21 am Monday.

Venus and Jupiter continue to dominate the evening sky, with brilliant Venus in the west southwest as darkness falls and Jupiter high in the east southeast. Venus sets at 9:45 pm and Jupiter is due south and highest at 10:40 pm.

Saturn rises in the east southeast at 12:55 am and is due south by 5:43 am.

By 8:15 Sirius, the brightest star in the night sky, is due south and at its highest, lying just over 30 degrees above the horizon. It is bright largely because it is one of our nearest numbers, ranking as the fifth most distant star from our own star, the Sun. It lies 8.58 light years from us, so the light you see tonight left Sirius in mid-August, 2006. Contrast this with our Sun, whose light takes only 8 minutes to reach us.

The International Space Station is now in the morning sky. If you are up early you’ll have chances to see nice passes of the ISS Sunday and Monday mornings. Both passes will feature the ISS moving out of the Earth’s shadow and coming into view when well above the horizon. (Some times here will be given in hours, minutes, and seconds.)

The pass Sunday morning begins at 6:01:42 am when the space station will appear, moving out of the Earth’s shadow and into sunlight, 24 degrees above the western horizon. It will appear near the two brightest stars in the back of Leo, the Lion, and will then move toward the Big Dipper. It will pass through the Dipper’s bowl at 6:03 am and will then pass below Polaris, the North Star. Just before 6:05 am it will move through the distinctive “W” of stars marking Cassiopeia, the Queen, and will vanish below the northeast horizon just after 6:06 am.

Monday morning’s pass emerges from the Earth’s shadow when even higher in the sky, and first appears 50 degrees above the northeastern horizon at 5:10:41 am. It will then move downward between the “W” of Cassiopeia and Cygnus, the Swan, but closer to Cygnus. (Some people know Cygnus as the Northern Cross.) It will vanish below the northeastern horizon at 5:13:14 am.

The ISS will return to the evening sky on April 2.

The Dudley Observatory Skywatch Line for Wednesday, March 11th and Thursday, March 12th written by Louis Suarato.

March 11 is the birth date of Urbain-Jean-Joseph Le Verrier. Born in 1811, Le Verrier predicted the existence of the planet Neptune by using celestial mechanics. Le Verrier noticed irregularities in the planet Uranus' orbit and, from those, calculated the position of Neptune. These calculations led the way for Johan G. Galle to visually locate Neptune in 1856, after only one hour of searching, and within one degree of the position predicted by Le Verrier. Neptune is too close to the Sun to observe these nights, but will emerge in the early morning skies in May. Wednesday evening, after sunset, before 8 p.m., look for Mars above the western horizon and below Venus. Use binoculars, or a telescope, to locate Uranus just 1 degree below Mars. Scan over to the eastern horizon to see Jupiter, the fourth visible planet of the night, about 45 degrees above the horizon. At 9:30 p.m., Jupiter's moon Io, will be occulted by the planet. Beginning at 11:28 p.m. Thursday night, Io will partially eclipse Europa for 4 minutes, dropping the Galilean moon's magnitude by 0.5. A harbinger of Spring, and the fourth brightest star in our sky, Arcturus, rises in the constellation Bootes at 9:30 pm. Look 10 degrees above Arcturus for the globular cluster, M3.

Saturn rises in the constellation Libra at 1 a.m. Thursday. At that time, Saturn will be 1 degree below the 66% illuminated, waxing gibbous Moon. The pair separate to 3 degrees above the southern horizon before dawn. Look for Antares, Scorpius' brightest star, about 9 degrees below Saturn and the Moon. One degree to Antares' upper right is the globular cluster, M4. Discovered by Phillippe Loys de Cheseaux in 1746, and catalogued by Charles Messier in 1764, M4 is the first globular cluster to have individual stars resolved.

March 12 is the birth date of another celestial mechanic. Simon Newcomb was born in 1835, and served as the astronomer with the United States Navy. Newcomb is quoted as saying, "We are probably nearing the limit of all we can know about astronomy."

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, March ninth and tenth written by Joe Slomka.

Now that Daylight Savings Time is in effect, the Sun sets at 6:54 PM and night falls at 8:28. Dawn begins at 5:42 AM and ends with sunrise at 7:16. The planet Venus is the brightest object in the darkening sky. Medium height in southwestern skies, Venus blazes with minus 4 magnitude. Under moderate powers, Venus appears about 84 percent illuminated. Venus sets at 9:37 PM.

Fainter Uranus and Mars are to Venus’ lower right. Rust colored Mars shines with first magnitude and, under high power, appears almost “full.” Elusive Uranus lies about one degree to Mars’ left. Uranus appears at about sixth magnitude. As the sky darkens, Uranus should be visible in binoculars as a tiny blue-green ball. Both planets should fit in the same binocular or finder scope view and set about 9 PM.

High in the East, Jupiter occupies Cancer. Jupiter is the second brightest object in the sky, at minus 2.5 magnitude. Binocular viewers are in for a treat when they look about six degrees to Jupiter’s right; they will see the beautiful “Beehive” star cluster. Night brings several interesting telescopic events on Jupiter. The Great Red Spot (a giant storm) is visible at 10:18 Monday, and 4:05 AM on Wednesday. On Tuesday, at 2:31 AM, the moon Ganymede occults, or hides, the moon Io. Ganymede starts to cross Jupiter’s face at 10:10 PM, Monday, followed by its moon at 1:05 AM Tuesday; both exit Jupiter by 4:43 AM, Tuesday.

Comet Lovejoy is still visible to naked eye observers under dark, rural skies. Despite flying away from Earth, the comet is still observed at about fifth magnitude. It lies about two degrees from Delta Cassiopeiae and about 2 ¼ degrees from seventh magnitude star cluster M-103. Lovejoy still circles Polaris and does not set. The nineteen-day-old Moon rises about 11 PM on Monday in Libra and remains up the rest of the night.

Saturn rises after 1 AM and appears as a bright extra star in the head of Scorpius. It also remains up the rest of the night. Most constellations are related to mythical people or objects. In the 16th and 17th centuries, new constellations were devised to celebrate newly discovered star patterns and high technology of the times. One of these constellations is Sextans, the Sextant. Sextans is found between Leo's front paws and the constellation Hydra.

Johannes Hevelius was a Polish astronomer in the port city of Gdansk. In 1641, he built a private observatory that included a 150-foot telescope. However, he did most of his work with a six-foot brass sextant. A sextant contains an arc, one-sixth of a circle and has a moveable arm that measures angles. In 1679, fire destroyed his observatory. He immortalized his loss with the invented constellation, Sextans, and rebuilt his observatory. Sextants still exist. Sailors use a version, which includes a small telescope on the swinging arm and mirrors. Along with an accurate clock and astronomical almanac, the navigator locates his position at sea. That skill is being lost to the increasing use of GPS to fix a position with unprecedented accuracy.

This is Dudley Observatory’s Skywatch Line for Friday, March 6, through Sunday, March 8, written by Alan French.

The Moon reached full early last Thursday afternoon so a waning gibbous Moon will rise early in the evening this weekend. The Moon rises at 6:58 pm Friday, 7:55 pm on Saturday, and 9:53 pm on Sunday.

One hour of the two hour change between Saturday and Sunday’s moonrise is due to the start of Daylight Saving Time this weekend. Remember to set yourclocks ahead one hour before going to bed Saturday night. We’ll return to Standard Time on November 1.

Venus continues to dominate the west southwesternsky as darkness falls. On its inner, faster orbit, it is now slowly catching up with Earth. Through a telescope it now appears 84% illuminated, like a small, gibbous Moon. Venus sets at 8:32 pm EST.

We think of the space between the planets as being empty, except for asteroids and comets, but the inner solar system actually contains a vast cloud of dust. This interplanetary dust is more prevalent as you get closer to the Sun and is largely confined to the ecliptic, the plane within which the planets orbit. It extends out past the orbit of Mars.

The particles in this cloud reflect sunlight, and its faint glow is visible as the zodiacal light and the Gegenschein. The zodiacal light appears as a faint pyramid of light rising up from the western sky as darkness falls or eastern sky just before dawn begins. It is best seen when the ecliptic is at a steep angle to the horizon. In the evening sky this occurs in February and March. (It is best seen during September and October in the morning sky.) With the Moon absent from the early evening sky by Sunday, it would be a good time to start looking for it. Indeed the next two weeks will be prime time for spotting the beautiful zodiacal light. The see it you’ll need western skies that are dark and free of light pollution, and a good view down to or close to the horizon. Look for it between 8:15 pm and 9:00 pm EDT. It will look like a pyramid of light, brighter toward the bottom and up the center, and slanted a bit to the south or left.

The zodiacal band of light actually extends all along the ecliptic, but it is faint and very difficult to see. It is brightest at the anti-solar point, the point opposite the Sun in the sky, and this Gegenschein (counter-glow)is best seen in autumn or winter around midnight, when it is high in the sky.

This is the Dudley Observatory Skywatch Line for Wednesday, March 4th and Thursday, March 5th written by Louis Suarato.

The 99% illuminated, waxing gibbous Moon rises at 5:03 p.m. Wednesday. The Moon reaches apogee, its furthest distance from Earth during this lunar cycle, at 8 a.m. Thursday. The Moon will be full at 1:05 p.m. Thursday, and combined with lunar apogee, will appear to be the smallest Moon this year. On average, the Moon is about 250,000 miles from Earth. The elliptical orbit of the Moon causes a variation in distances. The Moon's distance varies from 7% less than average at apogee to 6% more than average at perigee.

After sunset Wednesday, Venus will begin to appear approximately 25 degrees over the west-southwestern horizon. As the sky darkens, look for Mars about 4 degrees below Venus. Use binoculars to search for Uranus less than a degree below Venus. Jupiter will be about 22 degrees above the Moon in the constellation Cancer over the eastern horizon Wednesday. Look for M44, the Beehive Cluster, approximately 7 degrees above Jupiter. To the east of Jupiter and the Moon is the constellation Leo. Leo's brightest star, Regulus, shines between Jupiter and the Moon on Thursday. Shining at magnitude 1.35, Regulus is the 21st brightest star in the sky. Regulus rotates once around its axis in 15.9 hours. Our Sun rotates about once every 25 days. This rapid rotation causes Regulus' equator to bulge. Regulus is a binary star that can be telescopically split. Regulus passes through SOHO's LASCO C3 field of view every August. Saturn rises after midnight and will be 28 degrees above the southern horizon before dawn.

On March 6th, NASA's spacecraft, DAWN, is scheduled to rendezvous with the dwarf planet Ceres. Recent photos taken of Ceres by DAWN have identified bright spots on the dwarf planet. We will be getting more detailed images of these spots and other features as DAWN is captured by Ceres' orbit and begins mapping the surface. NASA has stated " By the time Dawn is in its lowest altitude orbit at the end of this year, its pictures will be well over 800 times better than Hubble's."

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, March second and third written by Joe Slomka.

The Sun sets at 5:45 PM; night falls at 7:19. Dawn breaks at 4:54 AM and ends with sunrise at 6:28.

The twelve-day-old Moon is well up at Sunset, high in the Southeast. It is up most of the night and sets before Sunrise.

In the Southwest, the Venus-Mars pair continues to be moderately high. Venus is the brightest of the pair. It remains at minus fourth magnitude all month. However, Venus is climbing higher daily, now chasing after Jupiter. Mars lies four degrees to Venus’ lower right. The first magnitude planet is separating from Venus and appears lower daily. Uranus lies about two degrees to Venus’ left. This sixth magnitude planet is usually difficult to find, but, tonight, is lies within the same binocular and finder scope view. Uranus appears star-like in binoculars, but in a moderately powered telescope, it has a distinctive blue-green color. Mars sets at 8PM, with Venus and Uranus setting a half-hour later.

Jupiter appears five degrees North of the Moon on Monday, and eleven degrees above it on Tuesday evening. These two nights are great for planetary observers. Jupiter has a whole series of events. At 8:32 PM on Monday, and 2:19 AM on Wednesday, the Great Red Spot (a giant storm) can be telescopically observed. At 9:26 PM on Tuesday, the Jovian moon Io begins to cross the planet’s face, followed by its shadow; both Io and its shadow leave Jupiter at 12:19 AM Wednesday. In addition, Ganymede actually occults, or hides, Io at 11:11 PM Monday; Io is also eclipsed by Ganymede’s shadow at 12:29 AM, Tuesday.

Saturn rises at 12:37 AM and is best seen in pre-dawn hours. It appears as creamy-white extra star in the head of Scorpius.

Mercury brings up the rear by rising at 5:31 AM in Capricornus. This elusive planet appears about 68 percent illuminated under moderate magnification in a telescope. In January, the Skywatch Line mentioned that Sirius, the brightest star in the constellation of Canis Major, was actually a double star. The companion is called Sirius B, or more commonly, “The Pup.” The Pup is now over ten arc seconds removed from Sirius, almost as far as it can travel from it primary star. This is tonight’s challenge object. The Pub is best seen just before nightfall, because Sirius’ brilliance overwhelms the smaller star in nighttime skies. Sirius B is a white dwarf, the hot compact remnant of a sun-like star. It weighs about as much as the Sun but is about Earth-size. At 8.6 light years, it is the closest white dwarf, which makes it relatively easy for amateur sky watchers to hunt for it. If Sirius is too bright, the observer can make an “occulting bar” from a thin strip of aluminum foil pasted over half the observing field, thus blocking the brilliant star.

This is Dudley Observatory’s Skywatch Line for Friday, February 27, through Sunday, March 1, written by Alan French.

The Moon reached first quarter on Wednesday so a waxing gibbous Moon will grace the evening sky this weekend. The Moon does not set until 2:28 am Saturday morning, 3:15 am Sunday, and 3:58 am Monday.

The Sun sets at 5:42 pm on Friday and at 5:45 pm on Sunday. The Sun rises just after 6:30 am

On Friday night the Moon will be high in the southeast as darkness falls. By 8:00 pm the lunar orb will behigh in the south near the feet of the Gemini Twins. At 8:00 pm on Saturday the Moon will be below the middle of the Twins. Look to the upper left of the Moon for a pair of stars, Pollux and Castor. Pollux, a yellow-orange giant star lying 34 light years away is the brightest star in Gemini and the one appearing closest to the Moon on Saturday.

Castor is the second brightest star in Gemini. It is 50 light years away and is a multiple star system, made up of three binary pairs of stars and so a total of six stars. Castor A and B are visible in moderate sized amateur telescopes, and were first observed by Giovanni Cassini in 1678.

Below and slightly left of the Moon you’ll find Procyon, the brightest star in the rather inconspicuous constellation Canis Minor, the Little Dog. The name, from the Greek, means “Before the Dog,” as it rises a little before Sirius, the Dog Star. Procyon is just over 11 light years from us.

It is a binary star. Irregularities in the proper motion of Sirius lead to the discovery of Procyon B in 1840, but it was not spotted through a telescope until 1896, when it was observed through the 36-inch refractor at Lick Observatory. (Proper motion is the slight movement of the nearer skies against the background of much more distant and thus apparently “fixed”stars.)

By Sunday night the Moon will be toward the east southeast and lower in the sky, with Jupiter to its lower left. Castor and Pollux will be to the Moon’s upper right and Procyon to its lower right.

If you find it hard to remember which star is Castor and which Pollux is, keep in mind that Pollux is closer to Procyon. Jupiter now transits (is due south and highest) at 10:36 pm, a convenient hour, and is well up and fine for observing by 8:00 pm, when it will be just under 50 degrees above the east south eastern horizon.

This is the Dudley Observatory Skywatch Line for Wednesday, February 25th and Thursday, February 26th written by Louis Suarato


The Moon reaches its First Quarter phase at 12:15 p.m. on Wednesday. At that time, the Moon can easily be seen 14 degrees above the east-northeastern horizon. After sunset, at about 5:30 p.m., the Moon will have moved to 60 degrees above the southern horizon, within the Hyades star cluster, in the constellation Taurus. Look above the Moon for the Pleiades star cluster. As with all First Quarter Moons, it will rise at noon, be high over the south at sunset, and set at midnight. That reddish star, 1degree below the Moon, is Aldebaran, Taurus' brightest star.

After sunset, look over the west-southwestern horizon for Venus above Mars by 2 degrees. The two planets will set around 7:30. While Venus and Mars are setting, the constellation Orion is high above the southern horizon. Follow Orion's belt to the southeast to find Sirius, our night sky's brightest star, shining at magnitude -1.45. Sirius, the brightest star in the constellation Canis Major, is almost twice the size of our Sun, and 8.6 light-years away. A light-year is approximately 6 trillion miles. Sirius and Aldebaran, along with Rigel in Orion; Capella in Auriga; Procyon in Canis Minor; and Pollux and Castor in Gemini, form the asterism known as the Winter circle.

Look to the east of Sirius to locate Jupiter shining at the same magnitude. Thursday, at 10:23 p.m., Jupiter's moon Europa reappears out of the planet's shadow. Saturn rises at 1 a.m. in Scorpius, and will be 28 degrees above the southern horizon in the pre-dawn sky. Look below Saturn for the globular clusters M80 and M4. M4 is 1 degree to the right of Scorpius' brightest star, Antares. Mercury, just past its greatest elongation, may be visible before 6 a.m., with a clear view just above the southeastern horizon.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, February 23rd and 24th written by Joe Slomka.

The Sun sets at 5:37 PM; night falls at 7:11. Dawn breaks at 5:05 AM and ends with sunrise at 6:39.

The six-day-old Moon rose this morning and, after sunset, glows in the southern sky. It sets around midnight.

The darkening sky reveals Venus and Mars in a close pair. Both nights find them about one degree apart. Venus is the second brightest object in the sky, after the Moon. It shares Pisces with Mars. Both fit within a binocular or finder scope view. Venus is minus 4th magnitude, while Mars is only first magnitude. Venus is brilliantly white, while Mars is a rust color. They separate the rest of the month. Both set around 8 PM.

While Venus and Mars attract attention in the West, Jupiter emerges in the East, and is highest at 10:53 PM. At minus 2.5 magnitude, it outshines the constellation Cancer. Telescopic observers can see the Great Red Spot (a giant storm) at 7:45, Monday. They can also see the moon Io begin to cross Jupiter’s face at 7:41 Tuesday, followed by its shadow; both exit by 10:25 PM. This is the season for Jupiter’s moons to eclipse each other. For example, Ganymede occults, or blocks, Io for five minutes starting at 8:42 PM, Monday; Ganymede’s shadow eclipses Io for seven minutes at 9:38 the same night. Jupiter sets at 6 AM.

Comet Lovejoy is receding from Earth and becoming dimmer. Now about sixth magnitude, it is about two degrees west of M 76, the Little Dumbbell Nebula, and about two-and-a half degrees west of the star Phi Persei. The comet is still circumpolar, which means it doesn’t set.

Saturn rises in Scorpius about 1 AM and is highest at Dawn. It appears as a creamy white extra star in the head of Scorpius. Saturn is always a visual treat in telescopes of any size.

Mercury brings up the rear. It rises at 5:31 AM and is about zero magnitude. Under high powers, it appears about half illuminated. The elusive planet is at greatest elongation from the Sun, which means it is the most favorable time to observe. Still, it is only about six degrees above the horizon.

Many scientific discoveries result from accidents – astronomy is no exception. Monday is the twenty-eighth anniversary of one such accident. At the Las Campanas Observatory in Chile, Ian Shelton, in an off duty project, tested a repaired telescope and photographed the Large Magellanic Cloud, a satellite galaxy to our own. When he developed the picture, he discovered a very bright star; walking outside, he sighted it visually. He had observed the first naked-eye supernova since 1885. Supernovae are quite common. But they are usually located in dim, distant galaxies; this one was next door, in astronomical terms. It could be easily studied and its makeup determined. Supernovae are important. The violent explosion creates all elements heavier than helium. The atoms that make our bodies and everything in the Solar System were made in the hellish temperatures and pressures of a supernova. As a result, we are all made of “star stuff.” While the remnant of this supernova is too far south for us to observe; the Crab Nebula, another supernova vestige in Taurus, is visible in amateur telescopes tonight.

This is Dudley Observatory’s Skywatch Line for Friday, February 20, through Sunday, February 22, written by Alan French.

The Moon was new on Wednesday so a waxing crescent Moon will grace the early evening sky this weekend. On Friday night a slender Moon will join Venus and Mars as darkness falls. The trio should make a fine photo, especially with a good foreground.

The Sun sets at 5:33 pm on Friday and at 5:36 pm on Sunday.

Venus should be easily visible soon after sunset, and by 6:30 pm on Friday the close grouping of Venus, Mars, and the Moon should be a lovely sight above the west southwestern horizon. Mars will be less than a degree above much brighter Venus, and the Moon will be just under three degrees to the right and slightly lower than the two planets.

By Saturday night the eastward motion of the Moon against the starry background will have moved it well away from Venus and Mars. You’ll find the lunar orb almost 13 degrees to their upper left.

Mars and Venus will be closest together, separated by just one-half degree, on Saturday night, with Mars to the upper right on Venus. Look for Mars to the lower right of Venus and a little more than one-half degree away on Sunday night. (Note that a pinkie held at arm’s length spans one degree.)

Beautiful Orion, one of the most widely recognized constellations, is due south and highest around 7:30 pm. It is very easy to spot – it contains several very bright stars and they form a very conspicuous pattern. Perhaps most distinctive is a line of three equally bright, equally spaced stars, slanting upward toward the right (when due south), that form Orion’s belt. Above the belt are two bright stars marking the Hunter’s shoulders. The most brilliant, reddish Betelgeuse, to the upper left, marks his right shoulder. Bellatrix, to the upper right marks his left shoulder.

In old star atlases, Orion is often depicted kneeling on his right knee, with his right foot on the ground. Bright Rigel, below the belt and to our right, marks his left foot, while fainter Saiph reveals his right knee. He is often shown holding a club over his head in his right hand, and a lion’s skin shield in his left hand, in front of him and to our right. Can you imagine these in the stars?

Orion is also wearing a sword, which can be seen as three stars hanging below his belt. If you look closely, you may notice that the middle star looks fuzzy. Binoculars or a telescope will show it is actually a cloud of glowing dust and gas – the Great Orion Nebula, a place of star birth. It is a gorgeous sight through a moderate size telescope under dark skies and a very popular

This is the Dudley Observatory Skywatch Line for Wednesday, February 18th and Thursday, February 19th written by Louis Suarato


The New Moon occurs at 6:48 p.m. Wednesday. The Moon reaches perigee, 221,826 miles, its closest approach to Earth during this lunar cycle, at 7 a.m. Thursday. When a New or Full Moon occurs close to perigee, you can expect higher, and lower, than normal tides. If you look above the west-southwestern horizon a half hour earlier, you will see Mars and Venus about 2 degrees apart. Mars, above, will be 97% illuminated, while Venus, below, will be 88% illuminated. Although the two planets look close, Mars is about 70 million miles further from the Sun than Venus at this time. Thursday evening, about 45 minutes after sunset, Venus and Mars will be 1.1 degrees apart. Look for the thin crescent Moon low on the horizon.

Uranus shines at magnitude 4.4 in the constellation Pisces, about 15 degrees above Mars. Uranus is now 1.925 billion miles from the Sun. Over the Eastern horizon, Jupiter is 27 degrees high. Jupiter is approximately 407 million miles from the Sun. Jupiter, 2 weeks past opposition, is 99.9% illuminated. Thursday, beginning at 7:35 p.m. EST, Io's shadow will fall onto Ganymede, dimming Jupiter's largest moon by 0.8 magnitude. Saturn rises in Scorpius at 1:25 a.m. Thursday. Saturn is 928 million miles from the Sun.

About 10 degrees to the right of Jupiter is the open star cluster, M67. Discovered by Johann Gottfried Koehler in 1779, at an estimated age of 3.2 and 5 billion years, M67 is one of the oldest known star clusters. There are older star clusters, but none as close to our solar system. The cluster contains about 500 stars, of which, more than 100 are red giants, like our Sun. Look for the M44, the Beehive Cluster about 8 degrees above Jupiter and M67.

Thursday is the birth date of Nicolaus Copernicus. Born on February 19, 1473, Copernicus was one of the first astronomers to formulate a model of the solar system where the Sun was at the center. This model became known as heliocentrism. Heliocentrism disputed the widely held belief at the time that Earth was at the center of the then known universe, known as geocentrism.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, February 16th and 17th written by Joe Slomka.


The Sun sets at 5:28 PM; night falls at 7:03. Dawn breaks at 5:15 AM and ends with sunrise at 6:50. As the sky darkens, planet Neptune lies low on the western horizon; by civil twilight, it stands seven degrees above the horizon, posing a challenge for observers. Neptune sets at 6:11 PM.

Brilliant Venus and dimmer Mars form a close pair in the Southwest; they continue to approach each other. Venus, at magnitude minus 4, is vastly brighter than Mars. However, Mars, two degrees above Venus, is easily identified by its distinctive rust color. Both set by 8 PM. Uranus lies about fifteen degrees above the Venus-Mars pair. The sixth magnitude planet has no bright landmarks nearby; the observer needs a finder chart to locate the blue-green planet. Uranus sets at 9:22.

Jupiter, now in Cancer, rose at 4:17 PM, and, by nightfall, lies high enough for observation. At 7 PM on Tuesday, telescopic sky watchers can see the Great Red Spot, a giant storm on the giant planet. Also on Tuesday, the Jovian moon Europa begins to cross the planet’s face at 10 PM, followed by its shadow at 10:35. Europa and its shadow both exit Jupiter by 1:31 AM, Wednesday.

Nightfall reveals three lesser members of our Solar System. Comet Finlay, at 13th magnitude, lies about eight degrees above Uranus. Uranus is brighter than Finlay and a finder chart is required to spot it amid myriad stars. It sets after 10 PM.

Comet Lovejoy is the easiest of the trio. It is relatively bright at sixth magnitude, but dims slowly as it recedes from our view. Lovejoy is now in Andromeda and easily found by looking for M 76, the “Little Dumbbell” nebula. The “Little Dumbbell” is about two degrees from the comet and much dimmer then the comet. Both appear in same binocular or finder scope views. A study of their appearance reveals why Charles Messier began his list of would-be comets. Lovejoy is so high that it is classified as “circumpolar,” which means that it doesn’t rise or set, but seems to circle Polaris, the North Star.

Finally, the asteroid 3 Juno was the third to be discovered in 1804. It orbits the Sun between Mars and Jupiter. Eighth magnitude Juno is found about two degrees below third magnitude Altarf, also known as Beta Cancri. Juno sets about 10:30 PM.

Saturn rises in Scorpius at 1:30 AM and remains up the rest of the night. It appears as an additional cream-colored star in the head of Scorpius. The hour before Tuesday’s sunrise sees Mercury about seven degrees above the eastern horizon. It is accompanied by a very thin crescent Moon. The Moon turns officially “New” on Wednesday.

In 1762, Charles Messier discovered his first comet. This is not an unusual event; comets have been observed for millennia - usually by accident. Messier wanted to observe them systematically by scanning the skies. While searching, he kept finding fuzzy things that looked like comets, but never moved. Comets travel across the sky. He listed over a hundred such objects, so he would not be fooled again. These objects (later identified as galaxies, star clusters and nebulae) form the basic list for beginning astronomers.

This is Dudley Observatory’s Skywatch Line for Friday, February 13, through Sunday, February 15, written by Alan French.



The Moon was at last quarter late this past Wednesday, so a waning crescent Moon is visible in the predawn skies. The evening skies will be moonless and dark. Last weekend we wrote about the decreasing angular separation between Venus and Mars in the early evening sky. This weekend finds them even closertogether. If you look at brilliant Venus above the southwestern horizon Friday night as darkness falls, you’ll see reddish Mars just under four degrees above it, and a little to the left. By Sunday evening the pair will be just over three degrees apart. They will be closest together next weekend, when there will be less than a degree between them.

We’ve written about the distances to the brightest stars in Orion, Betelgeuse lying 500 light years away and Rigel at 860 light years. Most of the bright stars we see are closer to us and few naked eye stars are much farther away. The brightest distant star is Deneb, a luminary of the summer sky that marks the tail of Cygnus, the Swan. It lies at a distance of about 1,500 light years. The most distant star visible to the unaided eye lies at a distance of about 8,000 light years, but it is a faint star.

Jupiter rises at 5:20 pm on Saturday and is due south and highest just after midnight. By late evening the gas giant is high in the southeast and well placed for observing. On Friday night at 9:00 pm three of Jupiter’s visible moons, Io, Europa, and Callisto will be strung out to the east (left) of Jupiter and the fourth, Callisto, will be well to the planet’s west. They are easily visible in any telescope, and may be glimpsed by sharp-eyed observers in steadily held binoculars. (Note that some telescopes reverse the view, and will show three moons to the right and one to the left.)

At 9:00 pm on Saturday night Ganymede will still be to the planet’s east, and Io, Europa, and Callisto will be to the west, with Callisto still well away from the planet. By Sunday Io and Ganymede will be to the east and Europa and Callisto to the west.

It’s fascinating to watch the moons from night to night. Io, the innermost moon, takes 42 hours to make one orbit around Jupiter, so its position changes quite rapidly. The second most distant from Jupiter, Europa,takes 85 hours to make one trip around, while Ganymede takes 172 hours. Most distant Callisto requires 17 days. Its position changes at a leisurely pace.


This is the Dudley Observatory Skywatch Line for Wednesday, February 11th and Thursday, February 12th written by Louis Suarato.

Wednesday, after sunrise, Mars and Venus will be separated by about 5 degrees. Look low over the west-southwestern horizon for the two planets. The much brighter Venus will be below reddish Mars. At the same time, Jupiter will be about 17 degrees above the eastern horizon. Look approximately 10 degrees to Jupiter's upper right for M44, the Beehive Cluster. The Last Quarter Moon occurs at 10:50 p.m., Wednesday night. The Last Quarter Moon is not half as bright as the Full Moon, as some may think. The long shadows caused by the angle of the Sun during this phase dims the brightness of the Moon to about 1/11th of the Moon when full. The First Quarter Moon is a bit brighter than the Last Quarter because during this phase fewer darker areas, such as maria, or lunar seas, are illuminated. Saturn rises in the constellation Scorpius just before 2 a.m. Thursday. Saturn and the Moon will be 8 degrees apart. Friday morning, the Moon will trail Saturn by about 5 degrees in the pre-dawn eastern sky. If you have a clear east-southeastern horizon, you may be able to spot Mercury before sunrise, as it rises just after 6 am.

These cold days of winter can be a challenge for outdoor telescopic observing, but there are alternatives for those who need to satisfy their astronomical interests without feeling the impact of wind chill factors. Locally, of course, are the planetarium shows at miSci in Schenectady. You can find the schedule of planetarium shows at http://www.misci.org/planetarium/planetarium.php. Local astronomy events can also be found on the Night Sky Network (http://nightsky.jpl.nasa.gov/). The Night Sky Network is a coalition of amateur astronomy clubs who bring the science, technology, and inspiration of NASA's missions to the public. Once you join the network, at no cost, you can pull up a calendar of events for your region.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, February ninth and tenth written by Joe Slomka.

The Sun sets at 5:18 PM; night falls at 6:54. Dawn breaks at 5:24 AM and ends with sunrise at 6:59.

The darkening sky reveals two bright planets and two dim ones. Eighth magnitude Neptune is ending its winter appearance, is quite low in the southwestern sky, and may be unobservable. However, Venus blazes at minus 4 magnitude. It is about sixteen degrees high and five degrees below much dimmer Mars. All three share Aquarius. Notice that Venus, during February, gradually closes in on Mars. All three set by 8 PM.

Twilight also reveals sixth magnitude Uranus. In Pisces, Uranus has no bright companion. The darkening sky reveals thirteenth magnitude Comet Finley only four degrees away. Finder charts for both can be found in astronomy magazines, websites and apps. Both set by 9 PM.

Jupiter, now in Cancer, rises before Sunset. It passed Opposition on the sixth, which means that Jupiter remains up for most of the night. At minus 2.6 magnitude, Jupiter is the second brightest object in the sky, after the star Sirius. AT 4:10 AM Tuesday, telescopic observers can see the Great Red Spot, a giant storm, on Jupiter. At 7:45 PM Tuesday, a telescope reveals Jupiter’s moon Europa beginning to march across the planet’s face, followed by its shadow. Both exit Jupiter’s façade by 10:53 PM.

Telescopic observers can find the asteroid 3 Juno just west of Hydra’s head. The eighth magnitude asteroid is about 170 miles in diameter. It lies about ten-and-a-half degrees to the lower left of the bright star Procyon. Juno lies due south at 11 PM and sets at 5:21 AM. Nightfall reveals fifth magnitude Comet Lovejoy, now in Andromeda. Binocular observers can find it about four degrees West of Andromeda’s bright star Almach. Lovejoy is now receding from Earth and gradually becoming dimmer. It sets at 3:50 AM.

The twenty-day-old Moon rises about 11 PM Monday in Virgo, and Tuesday in Libra. The waning Moon appears about sixty percent illuminated and remains up the rest of the night.

Saturn rises at 1:56 AM in Scorpius. It appears as a bright addition to the stars that form the Scorpion’s head. Saturn is highest just before sunrise. Saturn is a treat in any telescope. Its ring system never fails to astonish first-time viewers.

The past two weeks saw the Northeast as the victim of several winter storms. As bad as these storms were, they are small compared to storms on other solar system members. The most famous example is the Great Red Spot on Jupiter. This tempest has been continuously observed for three hundred years, and is probably older. The Great Red Spot is actually a high-pressure hurricane, larger than several Earths. Jupiter experiences ordinary thunderstorms that radio amateurs can pick up on ham radios. Saturn also periodically displays cyclones. In 2010, amateur astronomers discovered the Great White Spot, a thunderstorm over 100 times larger than earthly ones. Uranus displayed an outburst, with 500 miles-per-hour winds, that lasted five years. Neptune also periodically presents severe weather. Finally, our Sun is constantly flaring and sending out clouds of charged particles. Major corporations and governments retain solar scientists to predict Space Weather, so that satellites, communications and astronauts are protected.

This is Dudley Observatory’s Skywatch Line for Friday, February 6, through Sunday, February 8, written by Alan French.

Reaching full late last Tuesday, a waxing gibbous Moon will rise in the evening. Moonrise is at 8:08 pm on Friday, 9:05 pm Saturday, and 10:02 pm Sunday. The Moon will reach last quarter this coming Wednesday.

We’ve mentioned brilliant Venus dominating the southwestern sky as darkness falls. Above Venus you’ll find much fainter, reddish Mars. The pair will be just over seven degrees apart on Friday. By Sunday evening they will be just over six degrees apart. Venus sets at 7:24 pm on Saturday.

The sunlight illuminating Venus took just over 12 minutes to reach your eyes, so we can say Venus is 12.3 light minutes from Earth. Mars is farther away, lying 17.8 light minutes away. Venus is brighter mostly because its clouds are much more reflective than the surface of Mars. Venus reflects 65 percent of the incident light, while Mars only reflects 15 percent.

As we move to planets farther from the Sun, their distances grow increasingly large. Bright Jupiter, visible low toward the east as darkness falls, now lies just over 36 light minutes away, so the light you see was reflected off Jupiter’s cloud tops more than 30 minutes ago.

In 1676 Danish astronomer Ole Roemer used the moons of Jupiter to make the first quantitative measurement of the speed of light. He was looking at Jupiter’s innermost moon, Io, and timing its eclipses – that is, when it moved into the shadow cast by Jupiter. He noticed that as Earth was moving closer to Jupiter the time between eclipses became progressively shorter. When Earth was moving away from Jupiter, he found this interval was getting steadily longer.

Roemer knew that the orbital period of Io was not changing, and realized that the time differences were caused by the finite speed of light. Another Danish astronomer, Christen Huygens, did the calculations, and determined that light traveled at 131,000 miles per second. The actual value is 186,000 miles per second. Huygens’ result was off because Roemer’s time delay estimate was a bit off, and the diameter of the Earth’s orbit was not precisely known. But it was the first calculation of the speed of light – a real milestone in astronomy.

When you look at the stars, you are looking at light that traveled for light years. Betelgeuse, the star marking Orion’s right shoulder (from our view, the upper left star), lies at a distance of 500 light years, so it took the light 500 years to reach your eye. Rigel, variously depicted as either his left knee or foot, lies 860 light years distant. In contrast, Sirius, the brightest star in the night sky and found to the lower left of Orion, is just under 8 light years away. Think about what this means for the actual brightness of the two brightest stars in Orion.

This is the Dudley Observatory Skywatch Line for Wednesday, February 4th and Thursday, February 5th written by Louis Suarato.

February 4th is the birth date of Clyde Tombaugh. Born in 1906, Tombaugh discovered the dwarf planet Pluto in 1930 by comparing images of stars on photographic plates taken days apart. At a distance of 30 times greater than the distance from the Earth to the Sun, a view of Pluto, even through large ground telescopes, appears as a dim star. The view is about to change as NASA's New Horizon spacecraft approaches Pluto after traveling for 9 years across more than 3 billion miles of space. On July 14th of this year, New Horizons will be about 7,700 miles from Pluto, undoubtedly providing amazing views of the dwarf planet.

That bright "star" you've been seeing over the west-southwestern horizon is actually a planet, the planet Venus. A telescopic view of Venus will reveal its disk to be about 90% illuminated. Look for Mars approximately 8 degrees above Venus. Watch Mars and Venus draw closer each night until their closest approach on February 20th. At 7 p.m., Jupiter will be about 20 degrees over the eastern horizon. Jupiter reaches opposition on February 6th, when the Sun is directly opposite the gas giant, illuminating its entire disk. The 99% illuminated, waning gibbous Moon rises at 6:12 p.m. and will be about 10 degrees below Jupiter and 5 degrees to the east of Leo's brightest star, Regulus. Saturn rises at 2:17 a.m. Thursday in the constellation Scorpius.

There will be a very bright, but brief, International Space Station pass over our region, beginning at 7:14 p.m. Thursday. Look for the ISS to emerge out of the west-southwest, to the left of setting Mars and Venus, and continue northeasterly through Cetus, before disappearing into Earth's shadow in Pisces. The International Space Station currently has 6 crew members aboard performing numerous research experiments.

This is the Skywatch Line for Monday and Tuesday, February Second and Third written by Joe Slomka.

The Sun sets at 5:09 PM; night falls at 6:46. Dawn begins at 5:31 AM and ends with the Sun rising at 7:08.

The night sky is becoming very active with the Moon, five planets, two comets and an asteroid.

The Full Snow Moon rose at 4:19 PM on Monday. By civil dusk, it is already visible in the sky. Unfortunately, the Moon's position in Cancer might make observation of the asteroid Juno, in Hydra, and Comet Lovejoy, in Andromeda, difficult.

Four planets occupy the southwestern horizon and escape the Moon's onslaught. Venus and Neptune form a tight, one degree, pair in Aquarius. Venus blazes at minus fourth magnitude, while lower Neptune shines at eighth magnitude. Under high telescopic power, Venus appears 91 percent illuminated, while Neptune is a small blue-green dot. Both should be visible low in the southwest as the sky darkens. Both set by 7:10 PM.

Mars, also in Aquarius, lies about nine degrees above Venus. Under high telescopic powers, the Red Planet appears almost "full." It, too, should be far from the brilliant Moon and visible in the darkening sky. Mars sets at 7:58 PM. Uranus, in Pisces, is 26 degrees above Mars. Sixth magnitude Uranus has no easy guides, and requires finder charts found in astronomical media. Uranus sets at 10:14 PM.

Comet 15P/Finlay lies about eight degrees below Uranus. Finlay is a periodic comet that returns every 6.5 years. Thirteenth magnitude Finlay requires a telescope, dark skies and a finder chart from astronomical media. It is also so far west of the Moon, that it should be visible. Finlay sets at 9:36 PM.

Comet Lovejoy may possibly be observable tonight. Now at fifth magnitude, Lovejoy inhabits Andromeda. It appears about two degrees from the star Almach. Almach is a second magnitude star that is the last in the star chain that forms Andromeda. Both should fit in a finder scope or binoculars. Lovejoy sets at 2:57 AM.

Jupiter is tonight's fifth planet, despite its proximity to the Full Moon, the giant planet should be easily visible by 9 PM. At 4 AM Tuesday, Jupiter lies about five degrees North of the Moon. Telescopic observers should be able to witness the Great Red Spot, a giant storm, at 3:25 AM and 11:17 PM on Tuesday.

As the Sun sets, the giant constellation Orion appears. Canis Major, the Big Dog, follows at Orion's heels. Sirius, the Dog Star, is among the closest stars to our Solar System, at 8.6 thousand light-years. Although stars seem fixed in our sky, they are actually traveling in different directions and speeds. Sirius is one of these. In sixty thousand years, it will approach to 7.8 light-years and increase its brightness only marginally. Sirius is not a solitary star; it has a companion, appropriately nicknamed "The Pup." This star closely orbits Sirius once every fifty years. This star, a white dwarf, is much smaller and dimmer than the primary. Sirius B, as The Pup is formally called, is still a bit too close. In a few years, amateur telescopes may spot The Pup, once Sirius' brilliance is blocked. Sirius B is about the Earth's size, but has the Sun's mass.

Clear Skies, Joe Slomka

This is Dudley Observatory’s Skywatch Line for Friday, January 30, through Sunday, February 1, written by Alan French.

Reaching first quarter last Tuesday, a waxing gibbous Moon will brighten the night sky this weekend. The Moon will reach full late this coming Tuesday.

Venus continues to dominate the southwestern sky as darkness falls and does not set until just after 7:00 pm. A telescope will reveal it is now a small gibbous disk. Venus is covered by a thick layer of bright, essentially featureless clouds, so it is not a popular target for amateur astronomers and their telescopes. Since it orbits inside our Earth, it shows phases like our Moon. As Venus catches up with Earth we see less and less of its sunlit side and it grows larger. By early June it will appear less than half full through a telescope.

Jupiter rises just after 5:30 pm and is high in the southeast by 11:00 pm. We’ve mentioned that its four bright moons, Io, Europa, Ganymede, and Callisto may be glimpsed through any telescope. They appear as stars close to the planet, lie roughly in line, and their positions change from night to night. Sometimes one or more may be out of sight, either passing in front of or behind Jupiter.

A telescope magnifying 60 times (60 power) will clearly show Jupiter as a disk. The disk is not perfectly round, but appears slightly flattened, and a couple of dark belts, prominent features in the planet’s atmosphere, cross the disk. A careful look may reveal more dark belts and light zones and features within them.. .

The Dawn space probe was launched by NASA in 2007 to visit the largest asteroid, Vesta and the dwarf planet, Ceres. It entered orbit around Vesta on July 16, 2007, and spent 14 months investigating Vesta. It left the asteroid on September 5, 2012 and is now approaching Ceres.

Dawn started photographing Ceres at the beginning of December and will arrive there on March 6. It already has astronomers puzzling over a mysterious white spot. It will be exciting to get a close up view of Ceres.

Ceres was discovered on the first day of 1801 by Giuseppe Piazzi. In 1772 Johann Bode suggested an undiscovered planet might lie between the orbits of Mars and Jupiter. Piazzi was hunting for this possible planet, and at first Ceres was considered a new planetary member of the solar system. Bode believed it was the planet he had predicted.

Three more bodies orbiting between Mars and Jupiter were discovered in the next several years, Pallas, Juno, and Vesta. Sir William Herschel proposed calling these smaller bodies asteroids. In the recent debate over the definition of a planet, resulting in Pluto being changed to “dwarf planet,” Ceres was also also classified as a dwarf planet.



This is the Dudley Observatory Skywatch Line for Wednesday, January 28th and Thursday, January 29th written by Louis Suarato.

As Mercury approaches inferior conjunction with the Sun on January 30th, the two remaining sunset planets are Venus and Mars. Look over the west-southwestern horizon after sunset Wednesday to see Venus 11 degrees below Mars. Mark your calendar for the nights of February 21st and 22nd when the two planets will be less than a degree apart. The 69% illuminated, waxing gibbous Moon shines in the constellation Taurus below the Pleiades star cluster, and right of the Hyades star cluster and the star Aldebaran. Thursday night, Aldebaran will be 1.2 degrees south of the Moon. Comet Lovejoy Q2 is fading, and may be difficult to see with the bright Moon. Wednesday night, the comet will be between the constellations Perseus and Triangulum, near the open star cluster NGC 752.

An open star cluster is a group of up to a thousand stars formed in the same molecular cloud and loosely gravitationally bound to each other, as opposed to globular clusters, which are tightly gravitationally bound. Open star clusters are also known as Galactic clusters because they reside within the disk of the Milky Way. Open star clusters are important to the study of stellar evolution because these relatively young stars provide a sample of stars of similar age and chemical composition.

Jupiter rises at 5:47 p.m. in the constellation below Cancer and east of Leo. Look 10 degrees to the right of Jupiter for the open star cluster M67. Discovered in 1779 by Johann Gottfried Koehler, the stars in M67 range in age from 3.2 and 5 billion years old and is one of the oldest known open clusters. About 7 degrees above Jupiter and M67, is the open star cluster M44, or Praesepe, also known as the Beehive Cluster, in the constellation Cancer. At the distance of 520 to 610 light years, the Beehive Cluster is one of the nearest open clusters to our solar system. Saturn rises at 2:42 a.m. Thursday in Scorpius.

January 29th is the birth date of astronomer Philibert Jacques Melotte. Born in 1880, Melotte discovered a moon of Jupiter, and asteroid, and a small open star cluster known as Mel 111. Look for Mel 111 in the constellation Coma Berenices, about 10 degrees above the star Arcturus in Bootes.

This is the Skywatch Line for Monday and Tuesday, January 26th and 27th written by Joe Slomka.

The Sun sets at 5 PM; night falls at 6:38. Dawn breaks at 5:37 AM, ending with sunrise at 7:15.

As the sky darkens, the Moon and six planets become apparent. The First Quarter Moon is already high in the southern sky; it rose before Noon and sets after Midnight.

The Venus-Mercury pair that was close last week has split up. Venus, in Aquarius, blazes at minus 4 magnitude and continues to climb higher. Mercury, also in Aquarius, looks thinner and dimmer as it daily lowers in the sky. Mercury sets at 5:46 PM; Venus sets an hour later.

First magnitude Mars is moderately high in the southwest. The Red Planet appears as a tiny dot in the twilight sky. Mars still serves as a guide to dimmer Neptune. Eighth magnitude Neptune lies about five degrees to Mars' lower right, within most binocular and finder scope fields of view. Mars and Venus also share Aquarius.

Nightfall reveals Uranus, in Pisces. The sixth magnitude planet is far from any easy marker, requiring a finder chart from magazines, websites or apps. Uranus sets at 10:40 PM.

Comet Lovejoy moved into the dim constellation Triangulum. Still at fourth magnitude, Lovejoy is a binocular object. It lies about three degrees from Gamma and five degrees from Beta Trangulii; its also nine-and-a-half degrees below Algol, the brightest star in Perseus. Algol itself undergoes two hour periodic eclipse centered at 10:36 PM. Lovejoy sets at 2:27 AM.

Bright Jupiter rose at 5:54 PM in Leo and remains up the rest of the night. Telescopic observers can see the Great Red Spot, a giant storm, at 10:48 Tuesday night.

Saturn rises in Scorpius at 2:46 AM. Saturn appears as an extra star in the Scorpion's head. In binoculars or telescope, its creamy white hue identifies it. Telescopes reveal the beautiful ring system. Saturn remains up the rest of the night.

If one looks up at 7:00 PM on a moonless night, the Hyades star cluster is high and forms the horns of Taurus, the Bull. The "V" shaped constellation points to a large pentagon, the constellation AURIGA. If the "V" is extended, the upper horn joins the bottom star of Auriga. The lower horn stops at a star below. Train a telescope at that lower star, and look just above it. The hazy patch is the Crab Nebula. On July 4, 1054, a star exploded, shone brightly in daytime, and disappeared after about a year. The Crab Nebula is all that is left, a cloud of gas and debris, expanding at 600 miles per second, with a diameter of 6 light years and 6300 light years distant. Recent studies revealed that the remnant star is a pulsar, a very dense star that does not emit light, but radiation in regular bursts, hence the name. This radiation lights up neighboring gas in infrared light. This is the most conspicuous supernova remnant. In 1987, a star in southern skies similarly exploded.

Like the earlier star, this one became conspicuous in night skies and left behind an expanding debris cloud.

Clear Skies, Joe Slomka

This is Dudley Observatory’s Skywatch Line for Friday, January 23, through Sunday, January 25, written by Alan French.

Having reached new this past Tuesday, a waxing crescent Moon will grace the evening sky. Look for the Moon in the southwest as darkness falls on Friday. It will set at 9:11 pm. By Saturday it will be higher and in the south southwest, setting at 10:22 pm. Sunday will find it still higher and farther toward the south. It sets at 11:32 pm Sunday.

Jupiter now rises at 6:08 pm and is well placed for observation late in the evening. Any telescope will show Jupiter’s four largest and brightest moons, and they are fascinating to watch. From our vantage point they cross in front of the planet and vanish behind it. Spotting a moon as it moves in front of the planet can be a challenge, but the shadows cast by the moons are inky black and visible in even a modest telescope.

If you’re willing to brave the cold, have a telescope, and the skies are clear, there is a rare triple shadow transit on the face of Jupiter early Saturday morning. For about 30 minutes you can see the shadows of three of Jupiter’s moons on the planet’s cloud tops. The next triple shadow transit visible here is not until March 20, 2032, so it might be worth braving the cold to see this unusual event.

Callisto’s shadow moves onto the planet at 10:11 pm on Friday, followed by Io’s shadow at 11:35 pm. The shadow of Europa moves onto to Jupiter at 1:28 am Saturday morning, making a total of three shadows. The triple shadow transit ends at 1:52 am when Io’s shadow moves off the planet.

If you want to try seeing the moons themselves crossing the planet, Io moves in front of Jupiter at 11:55 pm Friday, Callisto at 1:19 am Saturday, and Europa at 2:08 am Saturday. Their visibility depends on the contrast between the moon and the Jovian feature it is crossing. They are often easiest to spot as they first move in front of the planet.

If you are up early Sunday morning the International Space Station (ISS) will pass high across the sky. We see satellites when they are up in bright sunlight and we are down in the Earth’s shadow and the sky is still dark. Sometimes a satellite, like the ISS, will emerge from or move into the Earth’s shadow as it glides across the sky. During this nice pass of the ISS you can watch it move out of the Earth’s shadow and come into view as it moves into sunlight.

The ISS will move into sunlight as it approaches a position between the bottom of the Big Dipper’s bowl and the top of Leo’s head. Simply be watching the area of sky below and in front of the dipper’s bowl just before 5:45 am. After it appears, the ISS will travel below the Big Dipper. Its path will take it past bright reddish Arcturus and then down to the southeast horizon. It will vanish below the horizon just before 5:49 am.


This is the Dudley Observatory Skywatch Line for Wednesday, January 21st and Thursday, January 22nd written by Louis Suarato.

Venus and Mercury have a new companion in the west-southwestern sky Wednesday after sunset. A 3% illuminated, waxing crescent Moon, to the west of Venus, forms a triangle with the two innermost planets. Binoculars should help to locate Mercury, which will be lower on the horizon, 3 degrees below the Moon, and more difficult to see with the naked eye. A telescopic view will reveal Mercury to be a 25% illuminated crescent. The face of Venus is 93% illuminated. Thursday evening, the 8% illuminated, crescent Moon will be above Venus and Mercury, and reside 5 degrees to the west of Mars. A binocular or telescopic view of Mars will also show Neptune 1 degree to its lower right. Jupiter rises around 6:20 p.m. to the east of the constellation Leo. Before dawn on Friday, from 4:06 to 4:20 a.m., Jupiter's moon Callisto will cast its shadow on neighboring moon, Ganymede. Ganymede will dim by 1.4 magnitudes during this event, causing Ganymede to go from the brightest of the Galilean moons to the dimmest. Saturn rises at 3:11 a.m. Thursday above Scorpius. Before dawn, look below Saturn for Scorpius' brightest star, Antares.

By Wednesday night, Comet Lovejoy Q2 will have moved beyond the Pleiades star cluster into the constellation Aries. You'll find the comet about 4 degrees south of Aries' third magnitude star, 41 Arietis. Another comet, 15P/Finlay, has also been in the news. Comet Finlay has brightened considerably from 10th magnitude last December, to 7th magnitude. Discovered by William Henry Finlay on September 26, 1886, Comet Finlay orbits the Sun every 6.5 years. You can find Comet Finlay with binoculars about 13 degrees above Mars. It was former Dudley Observatory Director, Lewis Boss, who determined that Comet Finlay and Francesco de Vico's lost periodic comet of 1844 (54P/de Vico-Swift-NEAT), were not the same comet. Although there were some similarities in their orbits, it was Lewis' observations that determined these were two different comets.

This is the Skywatch Line for Monday and Tuesday, January 19th and 20th written by Joe Slomka.

The Sun sets at 4:51 PM; night falls at 6:31. Dawn begins at 5:41 AM, and ends with sunrise at 7:20.

Five planets grace the darkening sky. Venus is brightest, low in the Southwest. At magnitude – 3.9, it outshines everything else. Under high powers, it looks almost "full." Dimmer Mercury is about four degrees below Venus, and appears about one-third illuminated. Venus sets at 6:34 PM, Mercury at 6:21. The pair separates slowly, and also climbs higher in the evening sky.

Mars is higher in southwestern Aquarius, but dimmer than Venus or Mercury. Its height makes it easy to spot. Mars shares Aquarius with Neptune. Neptune is normally difficult to locate without a detailed sky chart, but tonight eighth magnitude Neptune is only about a quarter degree from Mars. Both fit in the same binocular or finder scope field. Neptune's blue-green color contrasts with Mars's rust hue. Both set at 7:56 PM.

Nightfall finds sixth magnitude Uranus in its usual spot in Pisces. Finder charts are available from astronomical media. It sets at 11:07 PM.

Comet Lovejoy is easily seen as a fourth magnitude blur in Aries. Capital District observers are routinely reporting sightings. Lovejoy is rapidly heading northward. These nights, it lies between 9 ½ and 10 ¾ degrees west of the Pleiades star cluster (M 45). Moving about two fields west in binoculars or finder scope should reveal a round hazy patch – that is Comet Lovejoy. There are no other deep sky objects in the area to confuse you. It is highest in the South 7:04 PM, and sets at 2:46 AM.

Jupiter rises in Leo at 6:26 PM, replacing Venus as brightest object in the sky. Binoculars and telescopes reveal the four Galilean moons. Telescopes also show the Great Red Spot (a giant storm on Jupiter) at 2:12 AM and 10:03 PM on Tuesday. Jupiter is highest at 1:28 AM and remains up the rest of the night.

Saturn rises at 3:11 AM and appears as an extra bright star in Scorpius' head. The creamy white color distinguishes it from the Scorpion's fixed stars. Saturn's ring system is always a treat in telescopes. Saturn also remains up the rest of the night.

With Comet Lovejoy in the significant constellation of Aries, lets take a look at it. The constellation is usually listed as first in the Zodiac. At the time of the Babylonians, Aries contained the Spring Equinox. It also was the constellation that began the Babylonian, Assyrian and Jewish calendars.

Aries is prominent in Greek mythology. Phrixos and Helle were threatened by their stepmother. Their deceased mother appeared with a golden fleeced ram, and urged her sons to ride its back and escape. They did; however Helle fell off the ram into the sea. The Hellespont is named after him. Phrixos safely made the crossing and landed in Kolchis, on the Black Sea. He sacrificed the ram to Zeus in thanksgiving and hung its fleece on a tree. This is the Golden Fleece of the Jason and Argonaut saga.

Clear Skies, Joe Slomka

This is Dudley Observatory’s Skywatch Line for Friday January 16, through Sunday, January 18, written by Alan French.

I hope you were able to catch the close pairing of Venus and Mercury in the early evening sky last weekend. Saturday night, when they were closest, featured clear skies in our area. If you missed it, or would like to see them again and watch as Mercury moves away from Venus, they are still close and now a bit higher in the twilight sky.

Look for the pair around 5:15 pm. Venus will be bright and easy to spot, just a bit west of southwest and almost 11 degrees above the horizon. I found Mercury fairly easy to see by 5:15 and obvious by 5:25 pm. Look for it just over two degrees to the right of Venus and slightly closer to the horizon (a pinkie held at arm’s length spans one degree).

The distance between the pair is now increasing and Mercury is dropping lower relative to Venus. By Saturday night they’ll be over two and a half degrees apart, and by Sunday the separation will three and a half degrees.

Comet Lovejoy has been rapidly climbing higher in the evening sky. It is now at its brightest and obvious in binoculars, appearing as large hazy glow. Some people have reported it is faintly visible by eye. The comet is now well placed in the early evening. It will be due south and highest, and so at its best, at 7:32 pm on Friday, 7:23 pm on Saturday, and 7:14 pm on Sunday.

For the best view and your best chance of spotting it by eye, give your eyes some time to get used to the dark. Your eye’s pupil opens quickly, to admit more light, but there is also a chemical change that makes the retina much more sensitive. The biggest increase in sensitivity takes about 15 minutes, but improvement continues for 30 or 40 minutes.

If you look a little east of due south, high above the horizon, you should easily spot bright, reddish Aldebaran amongst a v-shaped pattern of fainter stars that outline the face of Taurus the Bull. On Friday Comet Lovejoy will be about one binocular field of view higher than Aldebaran and several binocular fields to the right (due south at 7:32 pm). Each following night the comet will be a few degrees higher and farther west (right) of Aldebaran.

Another landmark you can use to find the comet is the Pleiades, or Seven Sisters, a lovely star cluster that looks like a miniature dipper. It lies to the upper right of Aldebaran. On Friday night Comet Lovejoy will be to the lower right of the Pleiades. By Sunday it will to the right and slightly below the Pleiades. Scan about three binocular fields from the Pleiades to spot the fuzzy glow of Comet Lovejoy. Although photos show a nice tail, it has not generally been visible in binoculars.

If you have trouble spotting Lovejoy, you can find more information and a finder chart here

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This is the Dudley Observatory Skywatch Line for Wednesday, January 14th and Thursday, January 15th written by Louis Suarato.

The Venus, Mercury close encounter continues Wednesday night as the two innermost planets are 1.3 degrees apart. Look low over the west-southwestern horizon for the pair of planets. Mercury is at its greatest eastern elongation from the Sun at 19 degrees. Look to the upper left of the pair for Mars, in the constellation Aquarius, 18 degrees above Venus. Jupiter rises minutes before 7 p.m. between the constellations Cancer and Leo. The 32% illuminated, waning crescent Moon rises Thursday after 2 a.m. in Libra. Saturn follows, rising at 3:30 a.m. between Libra and Scorpius. Friday morning, awake before dawn to see Saturn 1.9 degrees to the south of the crescent Moon. It was 10 years ago Wednesday that the European Space Agency's Huygens probe soft-landed on Saturn's largest moon, Titan after being released from NASA's Cassini spacecraft. It is the most distant landing of any man-made craft. Early photos from Huygen's indicated drainage channels crossing a mainland into a sea.

Comet Lovejoy (C/2014 Q2) is now at 4th magnitude brightness as it travels alongside the constellation Taurus. Wednesday night, you can locate Comet Lovejoy approximately 17 degrees south, and 3 degrees below the Pleiades star cluster. The comet moves about 3 degrees per day, so look closer to the Pleiades' after Wednesday, as the comet sails to its right. If your skies are dark enough, you may be able to see Comet Lovejoy with the naked eye. A binocular view will reveal the comet's coma as a fuzzy circle, glowing from cyanogen and diatomic carbon, which glow green when sunlight passes through. Telescopes will unveil the comet's long tail.

The Five Rivers Environmental Education Center in Delmar is hosting a Winter Astronomy event Friday night, January 16th, beginning at 7:30 p.m., weather permitting. Center staff will provide a naked-eye overview of the winter sky and constellations. Members of the Albany Area Amateur Astronomers will provide a variety of telescopes for guests to view planets, deep sky objects and Comet Lovejoy! The program is free, but space is limited. Please call Five Rivers at 518-475-0291 to register by Wednesday, January 14. In the event of cloud cover, this program will be postponed. Dress warmly!

This is the Skywatch Line for Monday and Tuesday, January 12th and 13th written by Joe Slomka.

The Sun sets at 4:43 PM; night falls at 6:23. Dawn breaks at 5:43 AM and ends with sunrise at 7:24.

As the sky darkens, three planets appear in the southwest. Mars, while not brightest, is the easiest to see. The first magnitude planet becomes an obvious rust color moderately high. Mars sets at 7:50 PM.

Venus and Mercury form a tight duo very low on the horizon. Venus' -4 magnitude gives away its position; less brilliant Mercury is about one degree below Venus. Both appear gibbous. An unobstructed horizon and binoculars are required to find them. Both set by 6:15 PM.

By twilight's end, Neptune, in Aquarius, is easy to spot tonight. The blue-green planet lies only about five degrees above Mars; they appear in the same low power field of binoculars and telescopes. Uranus, in Pisces, is more difficult and requires a finder chart from magazines, websites or apps. Neptune sets about 8:30 PM; Uranus sets at 11:30 PM.

Comet Lovejoy is also visible after astronomical twilight. Now located in the tail of Taurus, the Bull, it's about five degrees away from the star E Tauri. The fourth magnitude comet is quite bright and, now that the Moon is absent, in prime position for binocular or telescopic viewing. Lovejoy is highest at about 8:10 PM and sets at 2:50 AM.

As Mars sets, Jupiter rises in Leo. Binoculars show some of the four Galilean Moons. Tuesday, at 1:27 AM and 9:19 PM, telescopes reveal the Great Red Spot (a storm larger than Earth) on Jupiter. The telescopic observer will witness the moon Io being eclipsed by Jupiter's shadow at 5:59 AM, Wednesday. It is highest at 2 AM, and sets during daylight.

Tuesday's Last Quarter Moon rises after Midnight in Virgo, two degrees from the bright star Spica.

Saturn rises at 3:36 AM and remains up the rest of the night. Saturn crosses Libra and is on its way to Scorpius. Any telescope reveals Saturn's glorious rings.

By nightfall, Orion is already high in the southeastern sky. The bright white star Rigel marks the mighty hunter's knee. A dim line of stars begins at Rigel and flows westward and downward until it disappears below the horizon. This is the river Eridanus. To see the full extent of this heavenly waterway, one must travel to Florida. There, Eridanus ends with the bright star Achernar, which literally means, "star at the river's end." The identity of this stream is a bit of a mystery. Ancient authors differ as to whether it refers to the Euphrates or Nile. Both rivers were revered from time immemorial. Both were the sources of water and bountiful harvests. It is no coincidence that all great civilizations were founded along the banks of great rivers. Ancients thought of Earth as sort of an island surrounded by a great body of water. The creation story in Genesis alludes to this view, as does Babylonian creation myths. The sky also bears out this vision. For several months we have observed water related constellations. Delphinus, the Dolphin, and Capricornus, the Sea Goat, began the procession, followed by Aquarius, Cetus and Pisces. Eridanus sustains this heavenly aquarium.

Clear Skies, Joe Slomka

This is Dudley Observatory’s Skywatch Line for Friday, January 9, through Sunday, January 11, written by Alan French.

This is a great weekend for sky watchers. We have a nice comet, easily visible in binoculars, and Venus and Mercury will be unusually close together in the evening twilight sky. Brilliant Venus will be a superb landmark for finding the elusive innermost planet. We’ll start with Venus and Mercury since you’ll need to look just after sunset.

The sky is dark enough to easily spot Venus by 5:00 pm. Look for Venus, the evening star, just a little west of southwest. At 5:00 pm on Friday Venus will be ten degrees above the horizon and fainter Mercury will be less than one degree to the lower right of Venus. (A fist held at arm’s length spans 10 degrees across the knuckles. A pinkie held at arm’s length spans one degree.)

Binoculars will improve your chances of spotting Mercury, especially if there are thin clouds or haze near the horizon. With clear skies you should be able to spot Mercury by eye, especially if you wait until the skies are bit darker – say around 5:15 pm. Buy don’t wait too long, Mercury sets at 6:04 pm and is likely to vanish behind distant trees or buildings well before then.

At 5:00 pm Saturday Venus will be a bit higher and Mercury just over one-half a degree away, still to the right and below Venus. This is the night they’ll be closest together. They’ll be slightly higher and a tad farther apart on Sunday, with Mercury to the right and just a little below Venus.

Comet Lovejoy has been easily spotted through binoculars even with a bright Moon in the sky and has been seen by eye before moonrise. This weekend the comet will be in Taurus, the Bull, and due south and highest at convenient times.

On Friday look for Lovejoy at 8:40 pm when it will be due south. It will be about as far above the horizon as the top of Orion, which you’ll find to its left. The comet will form a large, rough rectangle with Rigel, Betelgeuse, and Aldebaran. On Saturday the comet will be a bit higher and due south at 8:30 pm, and by Sunday it will be due south at 8:20 pm.

If you live where the skies are dark, simply look for a large fuzzy glow a bit more than half way to the zenith. Be sure to give your eyes some time, perhaps fifteen minutes, to adapt to darkness if you want a better chance to spot the comet by eye. (With the bitter cold, turn off the lights inside and allow your eyes to adapt to darkness before going outside.)

If you are unable to spot it by eye, try finding it with binoculars. Once you’ve found exactly where it is, try by eye again. Even if you can see it by eye, a binocular view will provide a better view, and may reveal part of its tail.

If you’re not having any luck spotting Comet Lovejoy, an Internet search will quickly turn up more information and sky charts showing its location.

This is the Dudley Observatory Skywatch Line for Wednesday, January 7th and Thursday, January 8th written by Louis Suarato.

The innermost planets put on a show this week as Venus and Mercury shine above the southwest horizon after sunset. Wednesday, Venus and Mercury will be 1.1 degrees apart, and will be less than a degree apart on the 8th through the 12th. You can begin looking for the pair after sunset at 4:37 p.m. Wednesday. Venus sets at 6:02 p.m., providing you with about an hour and a half to locate the brighter of the two planets and its dimmer companion. Venus is at -3.34 magnitude at a distance of 1.595 astronomical units (AU) or 148,335,000 miles away. Mercury shines at magnitude -.65 and is 1.149 AU or 106,857,000 miles from Earth. Both planets are at gibbous phases. Venus is 95% illuminated and Mercury is 79% illuminated.

A bright 91% illuminated, waning gibbous Moon will rise at 8:21 p.m., affecting your ability to clearly view deep sky objects, so concentrate your attention to the larger and brighter targets. You'll find 1.1 magnitude Mars about 20 degrees above the southwestern horizon after Venus sets. Over in the east, rising south of the Moon, is -2.04 magnitude Jupiter. You'll be able to see all four Galilean moons Wednesday night. Io will be on one side, while Callisto will be closest to the gas giant on the other side and further away, very close together, are Europa and Ganymede. Thursday night, Jupiter will be 5 degrees to upper right of the Moon.

Other bright objects to observe while the light of the nearly full Moon fills the sky include the Great Orion Nebula or M42 in the constellation Orion, and the Pleiades star cluster above Orion in the constellation Taurus. Both are naked eye objects, but are better seen through binoculars. The Great Orion Nebula is even more magnificent through binoculars or a telescope. Try to view the tight cluster of stars in the heart of the Great Orion Nebula known as the Trapezium. The Trapezium consists of six stars, with four easily seen. The five brightest stars in the cluster are within 1.5 light years of each other and are responsible for the illumination of the surrounding dust and gases. The Pleiades star cluster, also known as the Seven Sisters or M45, can be found to the right of Auriga's brightest star, Capella, and above Taurus' brightest star, Aldebaran. The Pleiades is one of the closest star clusters in the sky and its nebulosity enhances its appearance. Saturn, shining at magnitude .75, is a morning planet, rising at 4 a.m. Thursday in the constellation Libra. Saturn's ring tilt, relative to Earth, is 25 degrees.

This is the Skywatch Line for Monday and Tuesday, January fifth and sixth written by Joe Slomka.

The Sun sets at 4:35 PM; night falls at 6:17. Dawn breaks at 5:44 AM and ends with sunrise at 7:26.

The darkening sky reveals three bright planets. Mars is not the brightest, but the highest and most easily seen. It is moderately high in the southern sky. Mars sets at 7:54 PM.

Venus and Mercury are much brighter but lower on the southwestern horizon. Mercury is about six degrees high during twilight, while Venus is much brighter and seven degrees high. Venus is almost "full," while Mercury is gibbous. Notice their separation; during the next few days they come to within a full moon's width of each other. Both set by 6 PM.

The Moon, past full, rises during dusk, and remains up the rest of the night.

Nightfall reveals Neptune in Aquarius, while Uranus remains in Pisces. Neptune and Mars are about seven degrees apart; in two week's time, they too will have a close call – what astronomers name a quasi-conjunction.

Fifth magnitude Comet Lovejoy is being sighted with binoculars in the Capital District. Comet Lovejoy is currently in the constellation Eridanus, which forms a river of stars springing southwestward from Orion's star Rigel. The Full Moon may hinder observation, so start watching during twilight, before the Moon gets very high.

Jupiter rises in Leo at 7:28 PM, and is visible until sunrise. Telescopic observers can see Jupiter's Great Red Spot at 12:42 AM and 8:34 PM on Tuesday. At 4:05 AM Wednesday, the moon Io will be eclipsed by Jupiter's shadow, followed shortly thereafter by Callisto's shadow beginning to cross the giant planet's face.

Saturn, in Libra, rises at 4 AM, and slowly heads towards Scorpius.

Yesterday, January 4th, was the Christian feast of the Epiphany, otherwise known as "Three Kings Day." Who were these "kings?" Most likely they were Magi from the eastern empire of Babylon. Babylonians were famous for their astronomical skill. By 2000 BC, they identified all visible planets, the major constellations, the zodiac and the Saros cycle of eclipses. These priest-astrologers were very powerful and respected throughout the known world.

These dedicated sky watchers would certainly have noticed any new object or event in the night sky. While some think that a comet or supernova may have been the "Christmas Star." The prevailing opinion is that it may have been an astrological event: the most likely being at triple conjunction between Saturn and Jupiter during the year 7 BC. During the course of the year, Jupiter appears to: chase Saturn, catch up and pass it, turn around and pass Saturn again, and finally catch up with Saturn one more time before sailing eastward past it. This startling series of events took place in Pisces, a significant constellation. While we now know the planets to be worlds like Earth, to the ancients, stars and planets were messengers from the gods. When two planets, associated with the most powerful gods, keep meeting, the Magi knew something significant was about to happen. These scholars were also familiar with their neighbors. A search of Jewish lore provided the inspiration to set off for that distant land and a possible meeting with a new god-king.
Clear Skies, Joe Slomka

This is Dudley Observatory’s Skywatch Line for Friday, January 2, through Sunday, January 4, written by Alan French.

The Moon will reach full on Sunday, January 4, so the night sky over the weekend will be dominated by a bright Moon. The Sun now sets just after 4:30 pm. On Friday the Moon rises at 2:51 pm, on Saturday at 3:41, and on Sunday at 4:34 pm, just as the Sun is setting.

Last weekend Venus set just over an hour after sunset. This weekend finds Venus setting almost 80 minutes after the Sun and it stands about seven degrees above the horizon at 5:05 pm. With a good clear view to the west southwest, free of clouds and haze, look for elusive Mercury, the innermost planet, below Venus. You may need binoculars to spot Mercury against the twilight glow. If so watch as the sky darkens and see if you spot it by eye before it gets too low to see.

On Friday night Mercury will be two and a half degrees below and slightly right of Venus, the distance between them will be just over two degrees on Saturday and just under two degrees on Sunday. Watch during the coming week as the pair moves higher into the evening sky and Mercury, moving faster, closes in on Venus. The pair will be closest together on the evening of January 10.

The Quadrantid meteor shower peaks on Saturday night. Unfortunately the bright Moon will obscure all but the brightest meteors. The Quadrantids, although not as well know as the Perseids of August or Geminids of December, is a fairly prolific shower, although the duration of maximum activity is short.

If you are familiar with meteor showers you know they are named for the radiant – the area of the sky the trails of the shower members all point back towards. The Perseids radiate out of Perseus and the Geminids from Gemini, but you may be puzzling over the Quadrantids. This show is named for an obsolete constellation, Quadrans muralis, the mural quadrant, which used to occupy the northern part of Bootes. (A mural quadrant was a wall mounted instrument used to measure the positions of stars.)

About half of the modern constellations came to us through the Greeks, and were listed by Ptolemy in the second century. As navigators traveled to the southern hemisphere they added new constellations. When cartographers drew marvelous star atlases they added their own constellations. Things got a bit out of hand. In 1930 the International Astronomical Union adopted an official list of 88 constellations, the star patterns we know today.

Constellations like Quadrans muralis; Felis, the cat; Musca borealis, the Northern fly; Rangifer, the reindeer; and Triangulum minor, the little triangle; were declared extinct. But Quadrans muralis lives on thanks to the Quadrantid meteor shower.

The Dudley Observatory Skywatch Line for Wednesday, December 31st and Thursday, January 1st written by Louis Suarato

Start off your New Year's Eve by viewing a pair of planets just after sunset and a total of four planets before midnight. If you look low over the southwest horizon about 40 minutes after sunset, you should easily spot Venus. To the lower right of Venus, by about 3 degrees, you may be able to see Mercury. Binoculars should help if you can't see Mercury with the naked eye. As the sky darkens, look approximately 25 degrees to Venus' upper left for Mars in the constellation Capricornus. If you have a clear view of the southeastern horizon, you may be able to spot Comet Lovejoy C/2014 Q2 four degrees high at about 6 p.m. to the lower right of Rigel, the bright star below the belt of Orion. Comet Lovejoy Q2 is now shining at 5th magnitude. Jupiter rises a few minutes before 8 p.m. in the constellation Leo. Jupiter's moon, Ganymede, will be eclipsed at 10:22 p.m. followed by Europa's eclipse at 11:01. Io's shadow transit begins at 11:36 p.m., followed by Io's transit beginning at 15 minutes past midnight, leaving Callisto as the only Galilean moon.

If you're still awake celebrating the New Year, or an early riser, look to the east after 4:30 a.m. Thursday to see Saturn rise between the constellations Libra and Scorpius. The 89% illuminated, waxing gibbous Moon rises at 1:24 Thursday afternoon. The Moon will begin the cross the Hyades open star cluster around midnight.

On January 1, 1801, astronomer Giuseppe Piazzi, discovered the first, and largest, asteroid, Ceres. On December 1st, NASA's DAWN spacecraft took a photo of Ceres from a distance of 740,000 miles. DAWN will be captured into Ceres' orbit in March 2015 to deliver images of a much higher resolution. Ceres is currently too close to the Sun for observations from Earth.