Skywatch October 2001

 NOTE: Times given in the scripts are all local Schenectady, New York time.

Monday, October 1st. Written by Joseph Slomka.

The Sun sets tonight at 6:27, with night falling at 8:11. Dawn breaks at 5:20 AM, with sunrise taking place at 6:54 AM.

The Full, Harvest, Moon rises shortly after sunset. The planet Mars shines brightly due South. Mars now lies amid the handle of teapot-shaped Sagittarius. Earth recently passed Mars, and the Red Planet slowly recedes into the background; Mars is noticeably smaller than it was earlier this summer. By midnight, Saturn is found within the horns of Taurus, the Bull. Saturn appears as a creamy white object about 23 degrees high. Binoculars hint at its rings, but a telescope is needed to see its glorious ring system, along with its four moons. By dawn, Jupiter is well up in Gemini. It, too shines brightly, and is a grand binocular object. Finally, Venus appears at sunrise. Earth's sister planet blazes high in the East. In binoculars, it appears about 90 per cent illuminated. In coming weeks, notice how Venus changes as it grows larger.

At midnight, in the East, lies the constellation Perseus. Most pictures depict the hero as having one long and one short leg. One of the stars on the short leg, Algol, has been famous for centuries as a variable star. Every 2.87 days, Algol visibly dims. Since stars were supposed to be perfect heavenly bodies, a star that periodically brightens and dims must be a "demon star," which is the translation of its name.

Algol is an eclipsing variable, a star which dims because another body gets between it and our view. Recent observations revealed that the star system is more complicated. The primary star, which we see, is orbited by a larger but dimmer subgiant, which pours its matter onto the primary. This pair is orbited by a smaller star about 92 light years distant. While ordinary eyes cannot see this intricate dance, amateurs can still note Algol's cycles and wonder at its beauty. Tonight, Algol reaches mideclipse at 1:32 AM. Start observing Algol about midnight and see if you can track its phases.

Tuesday, October 2nd. Written by Jonathan Cassidy.

Full moon tonight. Tonight there will be no real darkness as our moon is full. When the moon is full it raises as the sun sets and sets as the next days sun rises. They are opposite each other as seen from earth. If you could be far out in space you might notice a line of the bright objects: The sun, earth and our moon, with the earth in the middle.

It is during a full moon that occasionally the shadow of the earth can fall on the moon and cause a lunar eclipse. To night we will not be so lucky, but it does mean that we will have no real darkness tonight. Go out and look tonight and remember your shadows as two weeks from now you can look again at night and you will see no shadows except those cast by man made lighting.

There are no shadows on the moon to see either. With the sun beating down on the entire surface of the moon facing us every thing we see is lighted in direct sun light. There are shadows behind these things but we can not see there from our vantage point. Thus this is a very uninteresting time to view the moon except for crater rays. These are the white streaks of material radiating from various large craters. Where the ejected material crosses a dark area they can be seen as lighter streaks, some can even be seen with the naked eye.

Wednesday, October 3rd. Written by Bob Mulford.

The bright, nearly full Moon rises before the end of evening twilight tonight and tomorrow night. Traditionally the full Moon in October is called the Hunter's Moon, and it really does give extra light to both hunters and farmers at this time of year. Here is why.

On the average, the Moon rises 50 minutes later each day. However, this is only an average; the actual difference between tonight's moon rise and last night's depends on the season. In the early fall, near the time of the Full Moon, successive Moon rises occur only about 20 minutes later each day. This means that in September and October, the nearly full Moon rises before dark for nearly a week. Last night, the full moon rose at seven minutes past 7PM. Tonight, Moonrise is at 7:30. Tomorrow evening the Moon will rise at 7:55. The bright light of the Hunter's Moon was especially important to earlier generations, before the use of artificial light was common.

The reason for the Hunter's Moon is as follows. The path the Moon follows across the sky as it orbits the Earth each month is called the ecliptic. The Moon moves eastward along the ecliptic 12 degrees each day, completing a full 360 degree revolution around the Earth each month. However, at this time of year, the ecliptic is nearly parallel to the horizon at the time the full Moon rises. Thus, the Moon does not sink very far below the horizon as it moves along its orbit from day to day, and it rises at nearly the same time for several days.

Thursday, October 4th. Written by Peter Jennes.

Shortly after sunset, Taurus climbs over the eastern horizon and brings with it a very interesting member of the solar system. The family member in the spotlight is the small but mysterious asteroid Vesta that is now looping its way through the Hyades open star cluster. Except for Vesta, all of the other known asteroids appear to be cold, unchanged fragments left over from the birth of our solar system. Vesta on the other hand, features a surface marked with the chemical signature of ancient lava flows; signatures that can only mean this asteroid once had active volcanoes.

While lava flows are easy to understand on planets and large moons, they are virtually impossible to explain on an asteroid only 325 miles in diameter. The problem comes about because lava flows require a molten core. The physics of creating a molten core in one relatively small asteroid and not in any other asteroid stretches the limits of scientific understanding. One theory postulates that Vesta formed from materials enriched in radioactive isotopes. These isotopes probably came from a nearby supernova that may have triggered the birth of our solar system. As the isotopes decayed, the heat they gave off melted Vesta's interior and caused the denser materials sink to the center while the lighter materials rose to the surface. This gave Vesta a differentiated cross-section and enabled lava to be forced out onto the surface. Eventually, the decaying isotopes no longer generated enough heat and Vesta froze into its present appearance.

Given the power of the Hubble Space Telescope, it wasn‚t long before astronomers used it to probe Vesta's surface. As Vesta rotated under Hubble‚ s gaze, astronomers found a crater the size of Ohio and eight miles deep, a crater so incredible that it exposes the asteroid‚s inner mantle. In comparison, if Vesta were the size of the Earth, that one crater would be the size of the Pacific Ocean and 200 miles deep. With the Hubble images, astronomers now have to explain how an object the size of Vesta could survive the event that created this crater. To find Vesta from an urban area, you will need a telescope and a finder chart. Although you won‚t see the crater, it is worth looking for this mysterious object as it moves through the Hyades.

Friday, October 5th to Sunday, October 7th. Written by John Schroer

This weekend brings the Moon close to a planet, a comet is now visible to small telescopes, and Jupiter and Saturn move into the late evening sky.

The Moon dominates the evening sky. Now shrinking in apparent size as it orbits the earth, the moon is approximately 17 days old. Skywatchers that observe the line between day and night on the Moon, called the terminator, are witnessing sunset on our nearest neighbor. By the middle of next week, the Moon will be at third quarter, having completed 75 percent of its orbit around the earth. On Sunday, October 7th, the Moon will be only 1 moon width from the Planet Saturn. In eastern Asia, the Moon will move in front of this ringed wonder.

When first noticed last December on images taken by the LINEAR 1-meter telescope in New Mexico, Comet LINEAR (C/2000 WM1) was still outside the orbit of Jupiter. But calculations by Brian G. Marsden of the Smithsonian Astrophysical Observatory suggested that it might become a fairly nice comet for binoculars or the naked eye by year's end.

It's been slowly brightening ever since. The comet is now visible in 6-inch and larger telescopes, assuming the night sky is dark and transparent. In the first half of this month it remains practically stationary. Look very low to the northeastern sky and find a bright yellowish star. This is Capella, the brightest star in the constellation of Auriga the Charioteer. Comet LINEAR C/2000 WM1 is now 5 degrees northwest or ten moon diameters from Capella. Much better views are expected in the coming months.

Saturn and Jupiter are now on the move, appearing in the eastern sky late at night. Saturn rises around 10:15 PM, in the constellation of Taurus the Bull. Saturn is the brightest of the lights in the eastern sky. Just look for its telltale yellowish color. Jupiter is for night owls, rising around 1 AM. Jupiter, due to its size and it being located half the distance that Saturn is, will be appreciably brighter. Again, look for the Moon to be near both of these planets starting on Sunday, October 7th.

Thank you for calling Dudley Observatory's Skywatch Line. For more information on Dudleyís programs and activities, log onto Dudley's website. http://www.dudleyobservatory.org

Monday, October 8th. Written by Joseph Slomka.

Tuesday, October 9th. Written by Jonathan Cassidy.

The Milky Way Glx. Can be seen to slowly leave our viewing area tonight. When it gets very dark notice that the hazy streak of light we call the Milky Way Glx. is at the top, or zenith of the sky. As the night progresses it will be seen to move to the west and set, just as the sun and moon do regularly.

We are leaving the season of the southern Milky Way. We will have to wait till June of 2002 to revisit some of our favorite nebulae in and around Sagittarius.

However do not feel sad for as the Milky Way moves toward the horizon it leaves the majority of the sky dark. It is dark because we are no longer looking at local stars in our galactic neighborhood. Instead we are looking up out the side of our galaxy, that is there are fewer things in the way. Where local stars and nebulae are fewest and we can expect to find galaxies beyond our own Milky Way.

Make a note of the setting of the Milky Way. If you have binoculars or any small telescope scan our home galaxy from the southern horizon till you loose it high over head. Note the texture and multitude of stars. Now point toward the east and see the lack of anything even when using binoculars or a telescope. Indeed there is less to see so we must look for fainter objects such as far away galaxies.

Wednesday, October 10th. Written by Ray Bogucki.

For a few weeks on either side of the autumnal equinox, certain aspects of the Earth's orbital motion change rapidly. An obvious example would be the change in the times of sunrise and sunset. In the 2 1/2 weeks since the equinox, we have lost almost an hour of sunlight, with the Sun setting 34 minutes earlier than it did on Sept. 22. This rapid change in the time of sunset produces some interesting effects. The Earth's 365-day orbital trip around the Sun causes the stars to rise 4 minutes earlier each night, or two hours earlier each month. This motion produces the seasonal parade of constellations across our night skies as the stars march in their inexorable westward motion. Yet, a month ago, in early September, we could find Vega and Deneb, two of the bright stars in the "Summer Triangle", near the zenith at nightfall, and tonight, as the sky darkens, we find them still hanging around the zenith. The reason, of course, is that while they are moving westward with the other stars, sunset tonight is an hour earlier than a month ago, so that we see them an hour earlier in the day. Indeed, the "Summer Triangle" will dally in our western sky well into the winter months. On Christmas Eve you will find Vega just setting in the northwest, as the Northern Cross with Deneb at its head, stands upright on the northwestern horizon.

Our distance from the Sun is also changing rapidly. Having swung through our farthest distance from the Sun last July 4, we are now moving towards perihelion, our closest approach to the Sun, on January 4, and, as the weather grows colder, each successive sunset finds us 26,000 miles closer to the Sun. This apparent anomaly is explained by the short daylight hours and the low angle of the Sun, which have a greater effect on our temperature than our distance from the Sun does.

Tonight and tomorrow, watch for the Draconid (DRAY-co-nid) meteor shower, whose meteors appear to originate from the head of Draco, the Dragon, above and a little to the west of Polaris. While this is usually a very modest display with, perhaps, only a few meteors per hour, there have been surprises. In 1933, 1946 and 1972 there were heavy showers, with one approaching 30,000 meteors per hour for a brief period. While your chances of seeing a real meteor "storm" are very small, they're better than your chance of winning the state lottery!

Thursday, October 11th. Written byPeter Jennes.

As a special note: due to recent solar activity, local sky-watchers should be on the lookout for northern lights both tonight and tomorrow night.

With the moon out of the evening sky, it is time to look for deep sky objects. One region you may want to look at is the Great Square of Pegasus. The Square is large and stands out because it is located in a fairly empty region of the sky. At first, the Great Square may not be as obvious as you would think because it spans nearly fifteen degrees or one and a half hand widths on each of its four sides.

To find this celestial winged horse, look east around 9 PM. The Great Square will be somewhat tipped to the horizon, looking like a diamond standing on end. The star nearest the horizon is Algenib and it will be about 45 degrees or nearly five hand widths above the horizon. Starting with Algenib and working clockwise, the stars marking the other corners are called: Alpherat, Scheat, and Markab. The brightest star in the Square, Alpherat, used to belong to Pegasus but is now associated with the constellation Andromeda. Scheat, the second brightest star in the Square, owes it brilliance to the fact that it is a supergiant red star and only 220 light years distant.

In contrast to the brighter stars marking the corners, the central region of the Square appears devoid of stars from light polluted locations. However, turn a pair of binoculars towards the center of the Square and see the difference. There are easily thirty stars just below naked eye visibility. With a dark site and good optics the number of stars becomes amazing.

The neck and head of the winged horse extend out as a chain of stars from Markab. Pegasus' nose is the bright star Enif at the end of this chain. Binocular users may be able to glimpse a dim fuzz ball of stars just past Enif. This is M-15, the finest globular cluster in the fall skies.

Looking off the opposite end of the Square, a line of dim stars extends away from Alpherat. Including Alpherat, if you count three stars to the left and then scan the region above the third star with binoculars, you may come across a rather large patch of fuzzy light. That fuzzy patch is the Andromeda Galaxy and the light you see is over two million years old.

Friday, October 12th to Sunday, October 14th. Written by John Schroer

Monday, October 15th. Written by Joseph Slomka.

Tuesday, October 16th. Written by Jonathan Cassidy.

The New Moon today. That is tonight will be dark as dark as night can get. If you can remember the shadows the moon cast two weeks ago, you notice tonight there are no moon shadow, indeed there is no moon.

If you can get away from the buildings and lights to a dark site you will have an opportunity to see objects outside our Milky Way galaxy. Sun set is at about 6:20 PM, thus by 8 PM you will find true darkness.

We are with out the moon and the Milky Way galaxy is setting in the west. This is a great opportunity to find other galaxies. It is possible with the naked eye to see two other galaxies from our location and they are both visible tonight or next month during the new moon.

Look to the top, AKA zenith, of the sky. Notice to the east of this spot a set of similar stars that form nearly a square or a diamond. Each side of this asterism is a full hand span across. From the East most star go to the east following a curved line of stars. Go out this line one dim and one bright star. Go northwest two dim stars and notice there a patch of fuzz. This dim fuzzy thing is the Andromeda galaxy.

Now go back to the line of stars and move in the opposite direction the same distance to find another bright patch. This one dimmer and can be seen only during the darkest time of each month from a very dark site, it is the Pinwheel galaxy.

Wednesday, October 17th. Written by Ray Bogucki.

With the absence of bright moonlight, the next few nights present a good opportunity to find the constellation Andromeda. Lying above and a little to the right of the "W" asterism in Cassiopeia, Andromeda boasts no very bright stars but it contains one of the best known celestial objects, the great spiral galaxy. A star atlas will show you exactly where to look. This galaxy, known as M 31, was noted over a thousand years ago by the Arab astronomer, Al-Sufi, who referred to it as "a little cloud". A telescope reveals an elliptical patch of hazy light, whose long axis is 5 times the diameter of the full Moon, with a dramatically bright center. M 31 is our nearest neighbor among the large galaxies and bears the distinction of being the most distant object readily visible to the unaided human eye. While light reaches us from the Moon in one and a quarter seconds; from the Sun in 8 minutes; and from distant Saturn in one hour and twenty minutes, light from the Andromeda Galaxy takes almost 3 million years to get here. The combined light of some 300 billion stars in M 31 that enters your eye tonight began its journey when the first proto-humans capable of self-reflection were just emerging from the mists of time and mastodons and saber-toothed tigers roamed over North America, well before the Ice Ages.

While you are observing M 31, keep a watch for Orionid meteors whose shower lasts for a week and reaches its peak this Sunday and Monday. The best time to watch is late evening, after the waxing crescent Moon has set. The Orionids are very dependable with perhaps 10 to 20 meteors per hour. They appear to radiate from the constellation Orion, which will be rising above the eastern horizon. The individual meteors move fast and usually generate persistent white trails.

The Orionids occur when the Earth passes through the debris left in the orbit of the famous Halley's Comet. This comet, which has been observed from before the time of Christ, returns once every 76 years from well beyond Saturn, crosses the Earth's orbit on the way in, swings around the Sun between the orbits of Mercury and Venus and then crosses our orbit again on its way out. When the Earth passes through the debris of the second crossing, it generates the Eta-Aquarid meteor shower in early May.

Thursday, October 18th. Written by Peter Jennes.

By tradition, star maps show Pegasus as the front of a winged horse hanging upside down. This constellationís most recognizable feature is the Great Square asterism. The Great Square spans fifteen degrees on each side in a fairly empty region of the sky. Around 9 PM, the Great Square sits tipped on end like a diamond about 45 degrees up in the east. The star nearest the horizon is Algenib and working clockwise, the stars marking the other corners are called: Alpheratz, Scheat, and Markab.

Algenib, known by its Bayer designation of Gamma Pegasus, is a magnitude 2.7 blue giant lying 333 light years away. Gamma Peg is a type of variable star known as a Beta Canis Majoris star. These stars expand and contract over a period of a few hours. During these rapid fluctuations, the star changes in brightness but the variations can only be observed with sensitive instruments. Stars like Algenib are all young, hot, blue giant stars that are just beginning to evolve off the main sequence.

The next star up from Algenib appears to be the brightest star in the Square. This star, Alpheratz, used to belong to Pegasus but it is now associated with the Andromeda. Not only does Alpheratz appear to be the brightest star in the Square; it is also the brightest star in Andromeda. That gives Alpheratz the Bayer designation of Alpha Andromeda. Alpheratz is a blue giant lying 97 light years from Earth. Because it is closer, Alpheratz appears to be nearly one magnitude brighter than Algenib.

Scheat, the second brightest star in the Square, owes it brilliance to the fact that it is a supergiant red star only 220 light years distant. Scheat varies in brightness from magnitude 2.1 to 3.0 over an irregular period. Scheat was one of the first stars to have its diameter measured. At Scheat's distance of 199 light years, astronomers calculated that this star is about 140 times bigger than our Sun. If Scheat were to replace our Sun, its outer layers would almost reach Earthís orbit.

The final star in the Square, Markab, is another blue giant. Markab lies 140 light years away and when Scheat is at its dimmest, Markab is one half magnitude brighter. Because Markab is slightly brighter than Scheat at times, it earns the Bayer designation of Alpha Pegasus.

Friday, October 19th to Sunday, October 21st. Written by John Schroer

This weekend witnesses the return of the Moon, a conjunction of the Moon and Mars, the two largest planets appear in the late evening sky, a meteor shower in Orion, and the possibility of northern lights to the Capital District.

The Moon is returning to the early evening sky. Now growing or waxing in apparent size as it orbits the earth, the moon is approximately 3 days old on Friday. Skywatchers that observe the line between day and night on the Moon, called the terminator, are witnessing sunrise on our nearest neighbor. The Moon will be passing near Mars on Monday the 22nd of October

Mars, the Red Planet, is now located in the southwestern sky during the early evening this weekend. This will be your last chance to see it before it disappears into the glare of sunset. The two largest planets, Saturn and Jupiter, are now on the move, appearing in the eastern sky late at night. Saturn rises around 9:30 PM, in the constellation of Taurus the Bull. Saturn is the brightest of the lights in the eastern sky. Just look for its telltale yellowish color. Jupiter is for night owls, rising around midnight. Jupiter, due to its size and it being located half the distance that Saturn is, will be appreciably brighter.

A solar storm, breaking out from a visible sunspot group, will be arriving this weekend, slapping against the earthís magnetic field. This will cause geomagnetic storms, including the Aurora Borealis ñ known as the Northern Lights. Look after local midnight, at a location away from city lights.

The Orionid Meteor Shower is peaking this weekend, with an average of 20 to 30 shooting stars an hour. Look after midnight towards the southeastern sky. Find Orion the Hunter by finding his three stars in a row which is his belt. The meteors will appear to come from the red star in Orion's shoulder, BEETLE JUICE.

Thank you for calling Dudley Observatory's Skywatch Line. For more information on Dudley's programs and activities, log onto Dudley's website. http://www.dudleyobservatory.org

Monday, October 22nd. Written by Susan French.

Early this evening, the International Space Station will be pass across the evening sky. It will appear about 10 degrees above the northwestern horizon at 6:21 PM. (A fist held at arm's length spans about 10 degrees across the knuckles.) It will be highest and brightest at 6:24. At that time is will be as bright as the brightest stars and 57 degrees high in the northeast. The Space Station will disappear in the east-southeast at 6:27.

The Northern Lights were visible last night in areas graced with clear skies, so keep an eye on the northern sky tonight to see if any activity remains. Aurorae often first appear as a dim, ashen glow. If the activity builds, streaks and curtains may appear, often tinged with shades of red. Tonight is the last of the peak nights for observing the Orionid meteor shower. The meteors may appear in almost any part of the sky, but if you trace their paths backward, they all point to the upraised club of Orion the Hunter. All meteor showers take their name from the constellation from which its meteors or ìshooting starsî seem to originate.

Some Orionid meteors are bright, but most are faint. They are very swift, and many exhibit colors. About 20% leave trails that linger for one or two seconds. Occasionally, you may see a fireball. A fireball is any meteor that is brighter than the stars or planets.

Orionid meteors come from material left behind by Comet Halley. When a comet visits the inner Solar System, it leaves bits of ice and dust behind. Right now the Earth is passing through Halleyís orbit and sweeping up debris shed by the comet. As this debris falls through our air it burns up and leaves a glowing column of air in its wake. Most shower meteors vaporize while they are still 60 miles overhead.

During peak days, the Orionid shower produces about 20 meteors per hour. Although the point from which the meteors seem to originate rises at about 9 P.M., it does not ride high in the sky until the early morning hours, so the best time for observing is in the predawn hours.

Tuesday, October 23rd. Written by Jonathan Cassidy.

Moon approaches Mars and there will be an occultation if you could see it in some parts of Africa.

In our area you can see tonight that the Moon and Mars are indeed very close. In fact since the Moon is at first quarter it is quite bright and you will not see many dim stars around it. The stars are still there but the Moon's brightness overpowers them, not Mars though. Mars is bright enough to shine through the Moon's brilliance. Look for it as the only bright object near the Moon tonight only.

The Moon moves each night a little east of the position it held the night prior. As the Moon is moving east each night the stars are moving west. This would be a formula for catastrophe if they were all moving on the same plane in the night sky. Of course we know that the Moon is relatively close by and the planets and stars are much further away.

However in ancient times they did not know this, or were prevented from revealing this geometry by powers of the time.

Though we know that the Moon does not collide with other objects each night it is possible to see close approaches and occultation. The word "occult" means mysterious or hidden. Indeed the Moon comes close enough to some bright objects to hide them and this would seem very mysterious to old civilizations.

Wednesday, October 24th. Written by Ray Bogucki.

This week marks a number of interesting events among the planets in our solar system. Yesterday evening, the space probe named Mars Odyssey arrived at the Red Planet after a 6-month trip. The spacecraft was scheduled to turn on its main rocket engine for the first and only time at 10:26 p.m., eastern daylight time. The craft then disappears behind the planet, where the engine shuts down automatically at 10:45 and, with luck, the Odyssey emerges from behind Mars and begins transmitting to Earth shortly after 11 p.m. By repeatedly dipping into the upper reaches of the Martian atmosphere, the highly elliptical, 19-hour orbit will gradually be slowed until the NASA engineers can stabilize it into a long-term, nearly circular, 2-hour polar orbit at about 250 miles above the surface. The Odyssey is equipped to send back details of the Martian surface and sub-surface. By tonight NASA will know whether the orbital insertion was successful.

Beyond Mars, the gas giant Jupiter will present an interesting sight as its two innermost planets cast their small black shadows on its surface at the same time. This Friday night at 11:43, the shadow of Europa, the second moon out, will begin its transit across Jupiter's face. 22 minutes later, it will be joined by the shadow of the innermost moon Io (EYE-oh). Moving faster, Io's shadow will overtake Europa's shadow and exit Jupiter's surface first at 2:18 a.m., followed 11 minutes later by the exit of Europa's shadow. Jupiter rises about 10:30, so it will still be low in the east at the start, but it will be well up in the southeast when the transit ends.

In the early morning, our two inner planets will hold an unusual rendezvous. Mercury, having just passed in front of the Sun is now rising rapidly in the east before sunrise, while Venus, preparing to swing behind the Sun, is slowly descending toward the horizon. The two are closing rapidly with Mercury lying about 4 degrees below Venus tomorrow morning, an hour before sunrise. By Saturday morning they will be within one degree of each other and, as Mercury turns and heads back toward the Sun, they will remain closer than one degree for the following 11 mornings. It is rare for these two to remain that close for such an extended period. A telescope with a wide-angle eyepiece will show them both in the same field, with Venus almost fully illuminated and Mercury about 50% lit, like the last quarter Moon.

Thursday, October 25th. Written by Peter Jennes.

As you probably know, everything went well late Tuesday night and the Mars Odyssey spacecraft is now in orbit around the Red Planet. At this time, the probe is beginning a series of orbital maneuvers that will last three months. During those orbits, the Odyssey spacecraft will use its solar panels as a sail to drag against the thin outer layers of the atmosphere of Mars. This process, called aerobraking, will slowly change the spacecraftís highly elliptical, 19 hour orbit into a 2 hour circular orbit.

Mars Odyssey is the 31st spacecraft sent to Mars. Not counting Mars Odyssey, only 10 of the first 30 missions achieved their objectives. The fact that only one spacecraft in three has been successful at Mars indicates just how hard this mission is. For Mars Odyssey, the mission is to deliver spectrometers and a thermal imager that will map the chemical and mineralogical composition of the Red Planet over the next two and one-half years. With any luck, these instruments will help solve the mystery of water on Mars.

While Mars is almost gone from the evening sky, the Moon will be very prominent. Tonightís lunar highlight is the crater Copernicus. Copernicus sits just above the lunar equator and between the Sea of Isles and the Sea of Rains. In a telescope, Copernicus boasts spectacular features including terraced inner walls, jagged ramparts, multiple central peaks, and a far-flung system of rays. Because of its location and features, Copernicus is one of the easiest craters to identify. Having found this crater, you can use it as a starting point to find other lunar features.

Immediately above Copernicus, a telescope reveals a compact chain of mountains known as the Carpathian Mountains. The Carpathian Mountains extend 200 miles and reach about 6,600 feet above the lunar surface. This range trends east to west and marks the southern border of the Sea of Rains. Using the Carpathians as a pointer, follow them to the east. As you do, you will cross a small lunar plain before you reach very nice crater with a prominent central peak. This is Eratosthenes, a crater that looks like a smaller version of Copernicus. Eratosthenes, also marks the southwestern terminus of the Apennine Mountains; the mountain range that forms the southeastern shore of the Sea of Rains.

Friday, October 26th to Sunday, October 28th. Written by John Schroer

 Monday, October 29th. Written by Joseph Slomka.

The Sun sets tonight at 4:52 PM, with night falling at 6:27. The virtually full Moon is already risen. Dawn breaks at 4:52 tomorrow, and ends with sunrise at 6:27.

Now that Daylight Savings Time ends, night falls earlier, and makes observing more convenient. As the sky darkens, Mars appears in the South. The normally difficult planet Neptune is only four and one half degrees to Mars' upper left. Both should fit in the same binocular or finder scope field. Neptune appears as a blue ball, while Mars is truly the "Red Planet."

The planet Jupiter shines brightly in the constellation Gemini. Telescope observers see cloud bands and other weather features. Saturn, the other giant planet in our Solar System, is the brightest light in the constellation Taurus. While Saturn can be seen in binoculars, only a telescope shows the beautiful ring system. The planet wobbles in its orbit, changing our view of the rings. Now they are tipped almost to the full extent possible, revealing its southern side, and great views of the ring system.

Jupiter is an interesting object for two reasons. First of all, Jupiter's atmosphere appears as a seething cauldron of various colors. This is evidence of titanic storms, many of which have lasted for decades; the Great Red Spot has been observed continually for about three hundred years. In fact it is possible to hear the storms. If you have access to a shortwave radio and directional antenna, you can hear the static these storms generate. A complex satellite system is Jupiter's other attraction. There are sixteen moons, of which four are visible to small telescopes and binoculars. At 8 PM, all four moons can be seen lined up on one side.

Jupiter's moons could not be more different. For example, Io is a forbidding place where volcanos spew sulphur and the surface is stained various colors. While Europa is a frozen wasteland; ice, many feet thick, covers the satellite.

Tuesday, October 30th. Written by Jonathan Cassidy.

Late each night now there is a cluster of stars low in the northeast, that everyone want to know more about. This group is a striking view in the night sky because it is so close to the horizon and it has several similar magnitude stars in a tight grouping. To some it looks like a very small dipper.

This is the Pleiades cluster. A true gravitationally linked cluster, not an optical cluster who's stars align visually but are millions of miles from each other. They all lie about 400 light years away in the Milky Way Galaxy.

According to "365 Starry Nights" photographic images show the Pleiades embedded in wisps of gas which shine by the light reflected from the stars. Some people think the nebulae are not linked but in front of the cluster.

Mythological legend identifies these stars as the seven daughters of Atlas. There are actually hundreds of stars in the cluster but only six can be seen reliably with the naked eye. To see seven, all the time, is not possible now. Light pollution was much less in ancient times and one of the star may have dimmed since then.

Take a look how many can you see?

Wednesday, October 31st. Written by Ray Bogucki.

Tonight, at 41 minutes past midnight, the Moon becomes 100% illuminated, thus producing the full Moon known as the "Hunter's Moon". The next full Moon occurs about 9 p.m. on November 30, the last day in November. It is a rare event for the short month of November to see two full Moons, inasmuch as the average time between successive full Moons is a little more than 29 and-a-half days.

The full Moon floods the night sky with enough light that only the brighter stars remain visible to the unaided eye, and most faint objects such as galaxies and nebulas are washed out, even in a telescope. However, planets are bright enough to be unaffected, so planet-watching is a favorite option on nights that have a full or nearly full Moon. Tonight, as the sky darkens, Mars can be found in the constellation Capricornus, low in the south. Mars currently has a new satellite. The Mars Odyssey arrived at Mars last Tuesday night and was placed successfully in orbit.

Two hours after sunset, the Ringed planet Saturn, shining at brighter than zero magnitude rises in the constellation Taurus. It is followed 2 hours later by the more brilliant Jupiter in the constellation Gemini. Until Mars sets about an hour later at 10:30, all three of the outer planets can be seen at the same time.

Still later, when the inner planets Venus and Mercury rise together about one-and-a-half hours before sunrise, Jupiter and Saturn are still high in the southwestern sky. Venus and Mercury will remain within one degree of each other for the next week. Venus, blazing at a magnitude of minus four is unmistakable, and serves as an excellent aid for finding Mercury, the elusive innermost planet.

Next Friday night should see a display of the southern Taurids meteor shower which results when the Earth encounters the dust stream left in the orbit of Comet Encke. The Taurids are usually modest in number and the still-bright Moon will be a hindrance. A second diversion that night is a double shadow transit on Jupiter. The shadows of Jupiter's two innermost moons, Io and Europa, will transit the surface of Jupiter from about 1:30 to 3 a.m. Saturday morning, in a repeat performance of last week's double transit.

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