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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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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."
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.
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.
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."
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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
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.
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.
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
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
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!
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 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.
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.
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
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.
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.
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