The Dudley Observatory

The Sun sets tonight at 5:44 PM. The waxing crescent moon, in the constellation Pisces, rises at 7:25 AM and sets at 8:07 PM. Mercury precedes the moon toward the horizon, setting at 7:08 PM. Look for Mercury near the western horizon after sunset.

While Mars is easily visible near the Pleiades in the constellation Taurus, the Bull, it is well past opposition and a disappointing target for amateur telescopes. Far more interesting is Saturn, shining at brighter than zero magnitude in the constellation Cancer, the Crab, near M 44, the Beehive Cluster. Both will be visible in the same field of view in ordinary binoculars. In a modest size telescope, Saturn will display its glorious rings, perhaps some detail on the ball of the planet, and several moons. At 10:00 PM tonight, looking through a Newtonian telescope, Enceladus will be to Saturn’s left, with Rhea below and slightly to the right of Enceladus. Both will appear relatively close to the rings, as will Dione and Tethys to Saturn’s right. Much further to the right will be Saturn’s largest moon, Titan. A Newtonian telescope has an inverted view, with West to the left, and North at the bottom. If you are using a telescope with an odd number of mirrored surfaces, the view is mirror reversed, with North at the top and East to the right.

Jupiter rises in Libra at 11:21 PM and is well placed before dawn. Jupiter is brighter than minus two magnitude and is, in many ways, the most interesting planet for amateur telescopes, as it shows the most detail on the ball of the planet, and the four Galilean moons can be followed in small telescopes. Unlike the moons of Saturn, the Galilean moons, and their shadows, often transit, or pass in front of, the planet. At 10:00 PM tonight, only three of the moon, Io, Ganymede and Callisto will be visible, as Europa will be behind Jupiter. In a Newtonian telescope, look for Ganymede far to the left of Jupiter, Callisto just below the planet, and Io to Jupiter’s right.

Finally, if you want to see the remaining naked eye planet, Venus, you will have to get up before dawn. Brighter than minus four and a half magnitude, Venus rises at 4:09 AM east of the Teapot asterism in Sagittarius.

And with the crescent moon setting early, don’t forget to go hunting for some deep sky objects.

Skywatch line for Thursday, March 2, 2006
by Ray Bogucki

The ancient Greek astronomers were well aware that most of the myriad stars they could see in their beautifully dark skies seemed to be fixed in place, always keeping the same positions relative to the other stars. A few bright objects, however, were not fixed but wandered restlessly among the fixed stars. They named these objects "planets", the Greek word for "wanderers". On rare occasions, one of these wanderers would slow down and then stop, remaining stationary for a day or so before moving again. This behavior was a source of great puzzlement to the ancients.

This was the situation with our innermost planet, Mercury, last night. Mercury has been climbing eastward, away from the Sun in the evening sky, but after last night's stationary pause, it will reverse its apparent movement and begin to drop back westward toward the Sun. This series of events occurs because Mercury is moving rapidly along its orbital path, preparing to overtake and pass the Earth on its inside track. For a short period, Mercury was traveling along a section of its orbit that pointed it straight toward Earth. In geometric terms, a straight line, tangent to the orbit of Mercury for that short period, would have passed close to our planet. An observer watching Mercury would see no eastward or westward motion of Mercury against the background of fixed stars. Of course, to a hypothetical observer on Mercury, the Earth would also appear stationary.

By a neat coincidence, the bright outer planet, Jupiter, now rising in the east about 11 p.m., will appear stationary this Saturday evening. Here the situation is reversed in that we are the inner planet and traveling along a section of our orbit that points our motion directly toward Jupiter, as we begin to overtake it. Jupiter will now appear to reverse its normal eastward motion and begin its westward or retrograde motion for the next four months. This retrograde motion is caused by the Earth's greater orbital velocity as it passes Jupiter, much as a car you are passing on the highway appears to be going backwards as you pass it.

We will pass between the Sun and Jupiter on May 4, placing Jupiter at opposition and giving us our closest approach to Jupiter for this year, and the best viewing of our giant neighbor.

The Sun sets tonight at 5:51, with night falling at 7:25 PM. Dawn breaks tomorrow at 4:48 AM and ends with sunrise at 6:21 AM.

The skies are full of interesting objects tonight. The First Quarter Moon lies high in the South; seven days old, it is half lit and blocks out many dimmer objects. Mars does not succumb to the Moon's brilliance; it shines to the Moon's lower right. The elusive planet Mercury can be spotted in binoculars low in the West, after sunset. The observer must work quickly; Mercury sets quickly and is easily hidden by trees. Saturn is already quite high in the southeast.

By nightfall, Mars points to the Pleiades star cluster to its upper right. Saturn also still lies close to the Beehive cluster in Cancer. Both pairs make an excellent binocular sighting.

By midnight, Jupiter joins the planetary club and is moderately low in the southeast. Jupiter and Saturn remain up, while Mars and the Moon set about 1 AM.

Venus rises before Dawn, blazes low in the southeast and replaces Jupiter as the brightest planet. In binoculars, Venus appears about one-third illuminated.

Also visible at Dawn is a visitor to our skies, a comet. Comet Pojmankski (poy-man-ski) was discovered by an Australian around Christmas. The comet is racing from southern skies northward and away from us. The comet's orbit implies that this is a one-time trip. It can be found just below the constellation Delphinus, the Dolphin. The constellation looks like a diamond with a tail in the East. The comet lies just below the tail. On Sunday morning, it appeared as a faint, fuzzy spot amid other dim, but point like stars. This Capital District observer had trouble finding it amid light pollution. Those living in more rural areas will probably have an easier time finding it. So, if you are up to a challenge, try to find it. This is a challenge object. If you find it, you may just get hooked on these remote visitors from the fringes of the Solar System.

Clear Skies

The Sun sets tonight at 5:53 PM. The Moon, which was at First Quarter on Monday, is in the constellation Gemini, and sets at 4:00 AM tomorrow morning.

Of the major planets, Mars and Saturn are visible at sunset. Mars is in the constellation Taurus, approximately seven degrees from Aldebaron and Saturn is prominent in the constellation Cancer, less than two and a half degrees below M 44, the Beehive Cluster. Jupiter, in Libra, rises at 10:53 PM and Venus rises tomorrow morning at 4:03 PM in Sagittarius.

At 10:00 PM tonight, the winter constellations of Orion, Taurus and Gemini are still prominent sinking toward the western horizon. Prominent high up, southeast of the pole, is Ursa Major. The Big Dipper asterism, the most prominent part of the constellation, is useful as a signpost. The so called pointer stars at the end of the bowl point to Polaris, the North or Pole Star and the stars in the handle can be used to “arc to Arcturus.” The pointer stars, Merak and Dubhe, in the direction opposite to Polaris, point in the general direction of the constellation Leo, the Lion. The two other stars in the bowl, Megrez and Phecda, point directly to Regulus, or Alpha Leonis.

Leo the Lion is a prominent constellation, which represents, and looks somewhat like, a crouching lion. The constellation is easily seen as a backward question mark, or sickle, in its western portion, with Regulus at the bottom, and a triangle in the eastern portion, the most prominent star, Denebola or Beta Leonis, bringing up the rear.

Leo contains five galaxies which are included in Messier’s famous catalogue of deep sky objects, and many fainter galaxies as well. Peering at Leo, we are looking out, away from the disk of our own galaxy, so the view is not obscured. Interestingly, several galaxies can be seen at the same time in a low power telescopic field.

One such group includes M 95, M 96 and M 105. M 95 and M 96 are spiral galaxies of 10^th and 9^th magnitudes, respectively, separated by less than three quarters of a degree. M 105 is a 9^th magnitude elliptical galaxy visible less than a degree away from M 96. A telescopic view will also reveal a barred spiral galaxy very close to M 105. All four can be glimpsed in a telescope affording a field of view of less than one and a half degrees wide. The galaxies can be found below and about one third of the way along a line connecting Regulus and Denebola. A basic sixth magnitude star atlas should be sufficient to locate the four galaxies, but you may have to wait for a moonless sky for a good view.

Dudley Observatory Skywatch Line for Tuesday, March 7th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

Sunrise today was at 6:24 AM, and it set tonight at 5:54 PM. Sunrise tomorrow will be at 6:22 AM and Sunset will be at 5:56 PM.

The Moon was at First Quarter phase yesterday, so it is in a waxing gibbous phase today. It rose at 10:43 this morning, and will set at 3:30 tomorrow morning. It will rise tomorrow morning at 11:37. Look for the Moon near the Planet Saturn on Friday evening.

The planet Mars, looking like an orange-yellowish star, is still near the star cluster known as the Pleiades, otherwise known as the Seven Sisters. The Moon will be near Mars on Sunday evening.

At the same time, the planet Saturn is high up in the south east. It is in between the constellations of Gemini and Leo.

The Planet Jupiter rises around midnight, and is also visible about an hour or so before Sunrise in the south. Venus, the brightest object in the Solar System after the Sun and the Moon, is in the east at around 6:00 AM. It is the only planet that can be viewed during the day.

The Winter constellations are high up in the south by 8:30 PM. Look for Orion the Hunter by spotting the three stars in a row that mark his belt.

Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Sky Above Mister Rogers Neighborhood”, a program for young people. At 2 P. M. is “Cowboy Astronomer”, and at 3 P. M. is a live narration of the Winter Sky. “Cowboy Astronomer” also plays Tuesday through Fridays at 2 PM.

The Moon is nine days old this evening and nearing full. The brilliance of the Moon is scattered by our atmosphere thus brightening the background of the night sky and reducing contrast with dimmer celestial objects. Reduced contrast makes faint deep-sky objects more difficult to see, so tonight may be a fine night to examine the lunar surface with a telescope or binoculars. The terminator is a term used to describe the dividing line between the Moon’s surface that is illuminated by the Sun and that portion of the lunar surface that is still in shadow. It is the region of sunrise or sunset on the moon. Today the moon is waxing full and the terminator describes lunar sunrise. Just as on Earth, the low angle of the illumination at sunrise or sunset cast long shadows which accentuate surface relief.

In his book The Modern Moon, Charles A Wood, opens his narrative of lunar regions with Mare Imbrium and the Imbrium Basin. This region and surroundings contains many geologic and topographic features key to understanding lunar origins. Nearly all lunar features are the result of collisions. Mare Imbrium itself is a lava filled impact depression and the surroundings show many details due to the uplifting caused by the impact. Mare Imbrium is the roughly circular darkish region to the upper left of center (lunar north and west). Along its northern rim can be found the crater Plato, conspicuous for its large size (62 miles in diameter) and flat, lava filled floor. The lava inside Plato’s rim is believed to cover a central peak over a mile in height. Scanning to the right, or lunar east, of Plato are the Alpine Mountains with the spectacular Alpine Valley, 6 miles wide and 100 miles long. Moving further clockwise around Mare Imbrium is the large partially submerged crater Cassini. Note the smaller more recent craters inside Cassini’s 35 mile width. South of Cassini are two more recent craters Aristillus, which has central peaks, and the smaller Autolycus which does not. West (left) of Autolycus is the large, 52 mile wide, lava flooded crater Archimedes. To the east of these three craters lie the Caucasus Mountains. Continuing clockwise around Mare Imbrium and lying south of the three craters, are the Apennine Mountains. The foothills of the Apennines is where the Apollo 15 mission landed in July 1971 and used a four wheeled lunar ‘dune buggy’ to explore Hadley Rille. The Apennine chain ends with the large rugged crater Eratosthenes. Further south and west lies the fabulous 34 mile wide crater Copernicus. Eratosthenes is believed to be between 1.1 and 3.2 billion years old, while Copernicus is than 1.1 billion years old. It is interesting to compare them since both have the terraced rims and central peaks, but only Copernicus has a large prominent ray system from the ejected material of impact.

This is the Skywatch Line for Monday, March 13
by Joe Slomka

The Sun sets tonight at 6 PM, ending with nightfall at 7:33. Dawn breaks at 4:35 AM, ending with sunrise at 6:09.

After sunset, three bright objects occupy our attention. Mars is high in the South, appearing tiny in our instruments. Saturn lies halfway up the southeastern sky. Binoculars show Saturn about two and a half degrees from the Beehive star cluster; telescopes reveal the beautiful rings. The Moon has just passed "Full" and is already up, low in the East.

Midnight finds Jupiter rising and Mars setting. By dawn, both Saturn and the Moon have set. Jupiter is low in the South, while Venus, in the East, outshines everything.

Space news has seen a busy week. The Mars Reconnaissance Orbiter successfully arrived. It joins a crowded Martian sky. Three other probes circle Mars: the US Global Surveyor and Mars Odyssey, also the European Mars Express. These satellites join Mars two natural moons: Phobos and Demos. In addition, both Mars Rovers are still chugging along, taking pictures and analyzing the Martian soil picture.

Jupiter also created headlines. Its Great Red Spot has been observed for approximately 300 years. Now a new "Great Red Spot Junior" shows up in the same vicinity. It previously was a white spot, now it turned red. Jupiter specialists are trying to figure out what this new development means for Jovian meteorology.

Finally, our own Sun hit the headlines. Solar observers have known for centuries that our Sun has an eleven-year solar cycle. The number of sunspots regularly rises and falls. But they could never predict when the cycle would start or finish, or how severe it would be. Now, a team of researchers concocted a computer simulation that dares to predict the next cycle. They predict that the first sunspots will appear late 2007 and the cycle will be about fifty percent stronger than the last. This is not idle speculation. The Sun's cycle is important for its influence on our weather, the operation of communication satellites, astronaut operations in space and the number of northern lights in our night skies.

Clear Skies

Joe Slomka

Dudley Observatory Skywatch Line for Tuesday, March 14th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum

Sunrise today was at 6:12 AM, and it set tonight at 6:03 PM. Sunrise tomorrow will be at 6:10 AM and Sunset will be at 6:04 PM.

The Moon is at Full Moon Phase tonight, rising at 5:58 PM, and setting at 6:28 tomorrow morning. The Full Moon of March is known as the Full Worm Moon.

Tonight is also a penumbral Lunar Eclipse, meaning that the Moon will pass through the outer lighter shadow of the Earth. The deepest part of the Eclipse occurs at around 6:47 PM, but generally speaking, Penumbral Eclipses are not very noticeable.

The planet Mars, looking like an orange-yellowish star, is still near the star cluster known as the Pleiades, otherwise known as the Seven Sisters.

At the same time, the planet Saturn is high up in the south east. It is located in the Constellation of Cancer, near the famous cluster of stars known as the “Beehive”.

The Planet Jupiter rises around 9:00 PM, and is in good view by 11:00 PM. Venus, the brightest object in the Solar System after the Sun and the Moon, is in the east at around 5:00 AM. It is the only planet that can be viewed during the day.

The Sun sets tonight at 6:01 PM. The waning gibbous Moon, in the constellation Virgo, rises at 6:54 PM and sets tomorrow morning at 6:42 AM, full Moon having occurred yesterday.

At 10:00 PM tonight, Mars is around first magnitude, sinking in the West. In the constellation Taurus, look for Mars about eight degrees above first magnitude Aldebaran. Saturn is prominent in the constellation Cancer at brighter than zero magnitude. Jupiter, brighter than minus two magnitude, rises at 10:25 PM in the constellation of Libra. Finally, Venus rises tomorrow morning at 3:59 AM in Capricornus. Brighter than minus four magnitude, Venus is a thick crescent, more than forty-four percent illuminated.

By 10:00 PM, Orion and Taurus are approaching the western horizon. In the southwest, Sirius, Alpha Canis Majoris, the brightest star in the sky is unmistakable, as is Procyon, Alpha Canis Minoris, a brighter than first magnitude star twenty-five degrees north of Sirius. Both are accompanied by white dwarf companion stars, first detected by the wobble they caused in the proper motions of Sirius and Procyon. White dwarfs are incredibly dense and heavy stars, at the end of their lives. No longer able to remain stable in size by converting hydrogen into helium, gravity condenses the star to a mere fraction of its original size.

Last Wednesday, we spoke of three galaxies in Leo in Messier’s catalogue of deep sky objects, M95, M 96 and M 105, visible in the same telescopic field. Leo contains two other galaxies from Messier’s list, both ninth magnitude spiral galaxies, also visible in the same field of view. M 65 and M66 appear about a third of a degree from each other, a little more than two and a half degrees below Theta Leonis, the third magnitude star marking the lower western corner of the triangle making up the eastern portion of the constellation. A modest size telescope will show both as elongated with condensed centers. Like the other Messier galaxies in Leo, a basic sixth magnitude star atlas will make finding them easy.

Skywatch line for Thursday, March 16, 2006
by Ray Bogucki

During the coming week, the Moon will pass very close to two different bright stars, Spica in Virgo and Antares in Scorpius. Tonight, the waning gibbous Moon will rise about 8 p.m. When it is well clear of the horizon, you will spot the bright, blue-white, first magnitude star, Spica, a little below and to the left of the Moon. The Moon will approach Spica all through the night. By 4 a.m. Friday, the pair will be at their closest approach in the west just before the beginning of morning twilight. The separation will be less than one Moon-width. In Hawaii, because of the different parallax, observers will see the edge of the Moon actually occult the star. On Monday night, after midnight, the Moon will rise close beside the bright red star, Antares. Again, the Moon will occult the star, but this occultation will be visible only from the northeastern tip! of South America at about 10 p.m. before the Moon rises here.

Monday, at 1:26 p.m., the center of the Sun will cross the celestial equator, marking the Spring equinox, when the Sun rises at about 6 a.m. due east and sets due west at about 6 p.m. This gives us about 12 hours of sunlight and 12 hours without the Sun. From that day on, the Sun will climb rapidly northward and stand higher at noon each day until June 21, when it reaches its farthest northward distance from the celestial equator at the summer solstice, when we experience over 15 hours of sunlight.

At this time of year the ecliptic, which designates our plane of travel around the Sun, rises steeply from the western horizon after sunset. This presents our best opportunity to glimpse the phenomenon known as zodiacal light. During the next two weeks, with the Moon absent from the evening sky, stand at a dark sky location and face west. As the evening twilight fades and dies, you can see a faint, ghostly white pyramid of light looming up from the horizon toward Mars and Aldebaran in Taurus, the Bull. This diffuse light is the reflection of sunlight from the countless tiny particles of dust generated by the collisions of asteroids in the asteroid belt beyond Mars. These particles orbit, and slowly spiral into the Sun over millions of years, making the inner Solar System a relatively dusty place.

This is the Skywatch Line for Monday, March 20, 2006
by Joe Slomka

The Sun sets tonight at 6:07, while night falls at 7:43 PM. Dawn breaks at 4:22 AM and ends with sunrise at 5:57.

As the Sun sets, Mars and Saturn shine through the darkening sky. Mars is high in the southwest. Mars is accompanied by nearby Aldebaran, the "Bull's Eye" of Taurus. They are approximately the same brightness and color, but very different. Mars is a planet; its color comes from its rusty soil. Aldebaran's color reflects its old, relatively cool and bloated star status.

Saturn shares the sky with Mars. As night falls, Saturn continues to lie close to Beehive star cluster, a glorious sight in binoculars. Telescopes provide stunning views of Saturn's rings and moons.

Jupiter rises about 10 PM in the southeastern constellation Libra. By midnight, it replaces Mars and Saturn, which are preparing to set.

By Dawn, Jupiter is well placed for telescopic observation of its weather systems and four Galilean moons. Dawn also finds Venus, low in the southeast and the Moon near Antares in Scorpius. Those in rural areas may also try to observe Comet Pojmanski, which is located just off the eastern wing of Cygnus, the Swan. The comet is now speeding away from us and becoming dimmer and higher in the sky on an apparent one-way trip through the Solar System.

Today's, main event was the Spring Equinox. This took place at approximately 1:26 PM. The Sun annually migrates from the southern to northern halves of the sky. This happens because two lines intersected; the ecliptic, the path of the Sun and planets across the sky, met the projection of Earth's equator on the sky. The days are steadily growing longer; today, night and day are equal, hence the name "Equinox." Virtually every culture celebrates the Spring Equinox in some fashion. Some think that Stonehenge, the English monument, was oriented to detect the Equinox. This is the time when priest-astrologers told their farmers to start planting. It also signals religious festivals. Both Hebrew and Christian calendars use the Equinox in calculating dates for Passover and Easter.

This is the Dudley Observatory Skywatch Line for Tuesday, March 21st, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

Sunrise today was at 5:58 AM, and it set tonight at 6:07 PM. Sunrise tomorrow will be at 5:56 AM and Sunset will be at 6:09 PM.

The Moon is at Last Quarter Phase tomorrow. Today it rose just after midnight, and will set at around 10:00 tomorrow morning.

Although Spring began yesterday afternoon, today is actually the first FULL day of Spring. The Sun rose exactly east, and will set exactly west, and although we usually hear that there are 12 hours of daylight on the Equinox, the Sun is actually up for 12 hours and 9 minutes. And beware of the old story that eggs can stand on their end on the first day of the Equinox. Eggs can be made to stand on their end on ANY day of the year.

The planet Mars, looking like an orange-yellowish star, is still near the star cluster known as the Pleiades, otherwise known as the Seven Sisters.

At the same time, the planet Saturn is high up in the south east. It is located in the Constellation of Cancer, near the famous cluster of stars known as the “Beehive”.

Skywatch Line for Wednesday, March 22, 2006
by Bernard Forman

The Sun sets tonight at 6:09 PM. The Moon, at last quarter, is visible in the morning, rising today at 1:35 AM and setting at 9:51 AM. The Moon rises tomorrow morning at 2:34 AM.

By 10:00 PM tonight, the winter constellations are sinking in the West, led by Orion and Taurus. Mars is in Taurus and is still prominent as a first magnitude object, though it is too small for telescopic viewing.

Saturn, brighter than zero magnitude, is in the constellation Cancer, the Crab, less than three degrees from the Beehive Cluster. Saturn is a magnificent object in any size telescope.

Ursa Major and Leo dominate the sky south of the pole. Below Leo can be found Hydra, the Water Snake. Hydra is the largest constellation in the entire sky. Hydra winds its way through the sky starting with its head below Cancer. Its head is above the celestial equator but its body thereafter moves south and east, ending below Virgo and Libra. In fact, only its head, made up of a group of six stars, is readily recognizable, although its brightest star, Alphard or Alpha Hydrae, marks the heart of the snake. Alphard is a second magnitude orange giant. Once you have located Hydra, it is relatively easy, with the help of a simple star chart, to find Corvus, the Crow, and Crater, the Cup, perched on Hydra’s back.

In the east, Bootes has already risen, led by zero magnitude Arcturus, the brightest star in the northern hemisphere, and the fourth brightest star in the entire sky. Arcturus is readily found by using the handle of the Big Dipper, by following the “arc to Arcturus”. Arcturus is, like Alphard, an orange giant star, but considerably closer at approximately thirty-six light years away. Its color should be perceptible without optical aid under good conditions.

Finally, Jupiter, at brighter than minus two magnitude, rises at 9:56 PM in the constellation Libra, although it is not very well placed for several hours. Although Jupiter is, usually, a magnificent object for almost any telescope, unlike Saturn it will not get very high in the sky this year for northern hemisphere observers.

Skywatch line for Thursday, March 23, 2006
by Ray Bogucki

During the coming week we will experience some interesting alignments of celestial bodies. On Wednesday, March 29, two of Jupiter's moons will pass between the giant planet and the Sun at the same time, casting their shadows on Jupiter's surface. Hypothetical observers along the paths of these shadows would experience a solar eclipse. From Earth, real observers with a telescope can watch the shadows of Io and Ganymede chase each other across the disk of Jupiter, beginning about 1 a.m. and lasting about an hour and a half. Jupiter will be well up in the southeast in the constellation Libra.

By far, a more spectacular alignment occurs on Wednesday a little later when the New Moon passes directly between the Earth and the Sun, causing the only total solar eclipse of this year. By a fortunate coincidence, the Sun, which has a diameter 400 times larger than the Moon's diameter, is also 400 times farther away than the Moon, so that our two most prominent celestial objects appear to have about the same size in the sky. Thus, when the Moon passes directly between the Earth and the Sun, it will block out the Sun completely, provided it is not near apogee, when it is farthest from Earth and its disk is not quite large enough to cover the Sun completely.

Wednesday's eclipse will begin with the Sun already totally eclipsed at sunrise at the eastern tip of Brazil. The Moon's shadow will race eastward across the Atlantic Ocean, making landfall in northwestern Africa. It will then cross the Mediterranean Sea, Turkey, the Black Sea and on into Siberia where the Sun will set fully eclipsed, three hours after the eclipse began.

The path of the Moon's shadow will be about 8900 miles long and, on average, 95 miles wide. Observers fortunate enough to be positioned along that path will watch the black disk of the Moon slowly creep across the Sun until the moment of totality when the sky will darken, the temperature will drop, stars will come out, birds and plants will assume nocturnal behavior and the ghostly white corona of the Sun will shine out from behind what looks like a round, black hole in the sky.

This is the Skywatch Line for Monday, March 27.
by Joe Slomka

The Sun sets tonight at 6:15 PM; night falls at 7:52. Dawn breaks at 4:09 AM tomorrow, and ends with sunrise at 5:44.

As the sky darkens, Mars and Saturn pop into view. Mars is a tiny red dot high in the southwest; Saturn is brighter, and almost as high in the southeast. Mars is located between the horns of Taurus, The Bull. Mars is too small for observation, but acts as a pointer for the first item on the Messier's list @ only four degrees to Mars' left.

Saturn, in Cancer, is a grand object. Any telescope shows its rings and larger instruments show a number of moons. Saturn remains close to the Beehive Cluster; any set of binoculars shows off this beautiful sight.

By midnight, Jupiter is moderately low in the southeast, within the constellation Libra. Jupiter is not near any interesting sights; but its four moons are easily seen in binoculars. A telescope reveals complex cloud systems. Recently, The Great Red Spot, a storm observed for 300 years, was joined by a smaller one, not far away. This weather in the making, and amateurs have a front seat.

The important, but dim, constellation Cancer lies bracketed between much brighter Gemini, Leo, and Hydra. The constellation itself is ancient, part of the original Mesopotamian zodiac. The first day of summer, on June 21, is the Sun's highest point of the year. In ancient Greece, this event took place in the constellation of Cancer. Since Cancer is located on the ecliptic, visits by the Sun, Moon and planets are common. On April 1, the Moon visits Cancer, eclipsing the Pleiades.

Cancer is an unusual constellation; its brightest feature is not a star, but a star cluster. If you live away from city lights, the first thing you see is a hazy patch in the middle of the constellation. This is M-44, the Beehive Cluster. When observed in binoculars or low power telescope, it resolves into hundreds of stars. These are born out of a common gas cloud and are found in the spiral arms of our Milky Way galaxy.

Clear Skies

Joe Slomka

This is the Dudley Observatory Skywatch Line for Tuesday, March 28th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

Sunrise today was at 5:45 AM, and it set tonight at 6:15 PM. Sunrise tomorrow will be at 5:43 AM and Sunset will be at 6:17 PM.

The Moon is in a waning crescent phase today, with the New Moon tomorrow. New Moon is the phase that we cannot see, as the Moon lies between the Sun and the Earth. Today it rose just at 5:24 AM, and it set at 5:37 PM.

With the changes in the seasons, the sky changes also. The winter constellations of Orion the Hunter, Taurus the Bull, and the Seven Sisters are now getting lower in the west after darkness. In the meantime, the Spring constellations of Leo the Lion and Bootes, are rising higher in the east.

The planet Mars, looking like an orange-yellowish star, is still near the star cluster known as the Pleiades, otherwise known as the Seven Sisters, but again, it is lower in the west.

At the same time, the planet Saturn is high up, almost overhead by 8:00 PM. It is located in the Constellation of Cancer, near the famous cluster of stars known as the “Beehive”.

The Planet Jupiter rises around 9:00 PM, and is in good view by 11:00 PM. Venus, the brightest object in the Solar System after the Sun and the Moon, is in the east before Sunrise. It is the only planet that can be viewed during the day.

Tonight, the sun sets at 6:17 PM. New Moon occurs today so, if we have clear skies, which have been highly unlikely of late, the Moon won’t interfere with our view.

At sundown tonight, Mars is high up in the west, in the constellation Taurus, the Bull. Dimmer than first magnitude, Mars has shrunk considerably since its opposition last November and is, accordingly, a disappointing object for amateur telescopes. Further up still, Saturn shines at brighter than zero magnitude in the constellation of Cancer, the Crab. Although Saturn reached opposition in late January, it is still a fine object for amateur telescopes.

Jupiter rises in the southeast at 9:26 PM in the constellation of Libra, the Scales. Not quite minus three magnitude, Jupiter’s apparent size is relatively large, and the planet’s cloud top displays a wealth of detail for amateur telescopes. The Galilean moons, Io, Europa, Ganymede and Callisto, can be followed as they move around Jupiter. The moons, and their shadows, can readily be observed transiting the ball of the planet. Of course, if one or more of the moons is “missing”, its behind the planet.

Venus rises Thursday morning low in the east south east at 3:49 AM. With sunrise occurring less than two hours later, a clear view of the horizon will be necessary to spot Venus which, at brighter than minus four magnitude, will be the brightest object in the sky.

By 10:00 PM tonight the winter constellations are slipping down toward the western horizon. The sky is now dominated by the spring constellations, particularly Leo, the Lion, which is a large constellation made up predominantly of second and third magnitude stars, besides first magnitude Regulus. Leo’s outline is discernable even under less than ideal conditions due to its relatively bright stars and recognizable shape.

With the winter constellations low in the west and the spring constellations in the south, we are, finally, able to get reacquainted with old friends we haven’t seen since last summer. Low in the northeast, as if trying to hoist himself into view above the horizon, we find Hercules. This is appropriate, since in Greek mythology, Hercules had to slay Leo as the first of his twelve labors.

Skywatch Line for Thursday, March 30
by Susan C. French 374-8460

A casual glance at the night sky shows us that not all stars are alike. There's a great range in their apparent brightness. A star may appear bright because it's relatively nearby, just as a nearby streetlight appears brighter than a more distant one. Or a star may appear bright because it's very luminous – a car headlight looks much brighter than a flashlight when the two are the same distance from you. Go outside, somewhere away from city lights, and look at the stars. The darker your observing site, the more stars you will see. If you are in a very remote area, you would be able to count about 2000 stars in the sky.

Although it is not as obvious, stars also come in a variety of colors. Most stars aren't bright enough to activate your eye's color receptors. And to make matters worse, the human eye is rather insensitive to color in tiny points of light. Thus only a few of the brightest and most strongly colored stars reveal their varied hues to the unaided eye.

Although distinguishing star colors is challenging, you can improve your chances by comparing and contrasting the brightest stars visible on any night. This is easier if the stars are fairly near each other. Look back and forth between pairs of bright stars. Eventually you should notice subtle differences. A few of the reddest stars are quite striking.

Binoculars or a telescope can make star colors easier to see, since they give the color receptors in your eye more light to work with. It also helps if you defocus the star images a little so that they are no longer point-like.

Stars vary in color according to their surface temperatures. The hottest stars have a bluish-white color. As you look at progressively cooler stars, they shade down through white, yellow-white, yellow, orange, and finally reddish-orange. You will notice that this spread of colors resembles a subdued rainbow except for the lack of green. Some people do see some of the blue-white or white stars as having a greenish tint, but most only notice this effect when a differently colored star is seen nearby.

Reddish stars are the easiest to distinguish. The differences between blue, white, and yellow stars require more scrutiny to discern. Look in the west when darkness falls tonight. There are several stars bright enough to show their yellow, orange, or blue-white tints. And if you turn toward the east, you should see the magnificent golden glow of the bright star Arcturus.

Skywatch Line for Friday, March 31, through Sunday, April 2
by Alan French

The Moon was new last Wednesday and is now moving toward first quarter. On Friday night you’ll see a pretty crescent Moon toward the west around 7:15 PM. You should be able to see the entire Moon, with the slender crescent brightly illuminated by the Sun, and the rest of the Moon faintly lit by the light of the nearly full Earth.

Skywatchers are in for a treat just after sunset Saturday night, April 1 (no fooling!). As the Sun sets the Moon will be among the stars of the Pleiades star cluster, also known as the Seven Sisters. The Moon’s eastward motion among the stars will move it across the stars of the Pleiades, hiding them from view. Any sort of optical aid – binoculars, spotting scope, or telescope - will reveal stars around the Moon. Watch for a while and you’ll see the edge of the Moon approaching a star. As it hovers at the edge, watch closely – the star will suddenly blink out and vanish from sight behind the Moon. The sudden disappearance shows the Moon has no atmosphere, and that the stars are so far away they appear as points of light.

Weather permitting the Albany Area Amateur Astronomers will host a public Star Party this coming weekend. At Star Parties a variety of telescopes are set up for your viewing pleasure, providing views of galaxies, star clusters, nebulae, and pretty double stars. Saturn is at its best right now, and will be a featured object at the beginning of the Star Party.

The Star Party is in Indian Meadows Park in Glenville, on Saturday night, April 1, beginning at 8:00 PM. Indian Meadows Park is off of Droms Road in East Glenville , and is marked by a large sign. After passing the park buildings, bear left at the fork in the road, and continue to a gravel parking lot on your left. The telescopes are set up beyond the gravel parking lot. Please park in the gravel lot and walk to the telescope area. If you are bringing a telescope, you may drive to the observing area, but try to arrive early.

There is no admission charge and all ages are welcome. You are welcome to stay as long or as briefly as you wish. Keep in mind that the temperature feels 20 to 30 degrees cooler when you are inactive under the night sky – so dress appropriately! It never hurts to have some extra layers of clothing in the car – some guests leave early because they get chilled. Star Parties are canceled if the skies are mostly cloudy.

Call Alan or Sue French at 374-8460 for more information or to verify a cancellation due to cloudy skies.