Skywatch February 2003

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

Friday, January 31st to Sunday, February 2nd. Written by George Mileski

On Saturday February 1st, there is a new moon. On Sunday 45 minutes after sunset, check out the young crescent moon, and use binoculars to find it. On Saturday looking east, one hour before sunrise the planets Mercury, Venus, Mars and Jupiter are lined up in the early morning sky. Jupiter is at opposition on the night of February 1st, it shines at -2.6 magnitude and is up all night from sunset to sunrise. 

You don't need a telescope to explore the wonders of deep space. All you have to do is lie back, with your star charts and look up. Humans have watched the stars overhead for thousands of years, but they didnot understand what the tiny lights signify. You can see over 40 deep-sky objects without a telescope, a handful of those are visible even from a city. I am not going to cover 40 objects here, but a good start is the "Pleiades star cluster". Its tiny dipper shape is easy to pick out on these chilly winter evenings. A few degrees south of the Pleiades lies another star cluster, the Hyades. Ruddy Aldebaran appears to be the brightest member of this grouping, but in fact it is a foreground star, so it is not a member of the Hyades cluster. 

From our latitude only one gas cloud or nebula is bright enough to pierce through the light pollution. Thats the Orion Nebula or M42. It can be spotted as the fuzzy middle star of Orion's sword, which hangs down from the three belt stars. Also look at all the bright stars in that area, Sirius, Rigel, Betelgeuse, Capella and others, they form a huge celestial "G". You can also use your naked-eye skills to follow the brightness changes of some of the brighter variable stars. Some like Algol in Perseus vary in brightness because they are eclipsed by a less-luminous companion. Algol normally shines at magnitude 2.1, but during a 10 hour period it fades 1.3 magnitudes and then returns to normal, then 2.9 days later it fades again. 

This was just a preview of some of the objects in the winter sky that can be seen naked-eye. 

Monday, February 3rd. Written by Joseph Slomka.

Tuesday, February 4th. Written by Jonathan Cassidy.

The slim crescent moon lies in the water this evening. That is it is between Pices, the fishes, and Cetus, the sea monster. Both these constellations have relatively dim stars compared to the stars of the winter circle.

The ecliptic, or path of the sun, goes through 12 constellations in its circle of the earth. Pices is one of these, it is setting in the west now as the sun sets. Cetus is just to the south.

After Pices the ecliptic, and the moon, pass through several more constellations we can see tonight. Next the east is Taurus, Gemini, Cancer and Leo on the eastern horizon.

You will find the brightest stars along the ecliptic in the constellations of Taurus and Gemini. Constellations to the north and south of these two also have bright stars. Most people will quickly pick out the three stars of the belt of Orion. Some people will notice the large lopsided "circle" of stars. These are (from farthest going south clock wise): Sirius, Procyon, Pollux, Castor, Capella, Aldebaran, Rigel and back to Sirius.

There are several other notable points of light in the sky now. Saturn is in line with orange Aldebaran and the twins Pollux and Castor. Jupiter is to the west of the same twins.

Wednesday, February 5th. Written by Ray Bogucki.

The next few mornings present observers with a last opportunity to glimpse the planet Mercury, around 6 a.m., an hour before sunrise. Brilliant Venus is unmistakable, well up in the southeast, while Mars shines at first magnitude 20 degrees to the right and above Venus; Mercury at zero magnitude is near the horizon, 20 degrees below and to the left of Venus in a rough line with Mars. Mercury is now dropping back toward the Sun. In a few week it will pass behind the Sun at superior conjunction.

In the evening sky, the constellation Gemini, the Twins, is high up in the eastern sky between the planets Jupiter and Saturn. From its position between two planets, one can calculate that Gemini lies on the ecliptic, the imaginary circle in the sky travelled by the Sun as the Earth makes its annual orbit around the Sun. All of the planets and the Moon travel in a narrow band on either side of the ecliptic, because the planes of all planetary orbits are close to the plane of Earth's orbit. The constellations that lie along this path are known as the twelve constellations of the Zodiac. Gemini holds a special place in this group because at the summer solstice, on June 21, when the Sun has reached the northernmost point in its travel, and we experience our longest day, the Sun will be in Gemini, near the toe of the Twin, Castor.

Gemini is home to many interesting sights. It contains one Messier object, the elegant open star cluster M35, which is visible to the naked eye in a dark sky, as a cloudy patch close to Castor's toe. Because it is near the ecliptic, M35 is occasionally occulted by the Moon. This presents a fascinating sight to telescope viewers who can watch the edge of the Moon block out dozens of stars in succession as it drifts across the cluster. Gemini also harbors several bright variable stars and the famous "Eskimo" nebula, a planetary nebula which, in photographs from large telescopes, looks remarkably like the face of a person surrounded by the furry hood of a parka.

Historically, two outer planets of the solar system were discovered while they were in Gemini. In 1781, William Herschel first recognized that the faint bluish object then located near the midsection of Pollux was not a star, but a new planet, later named Uranus. 150 years later, Clyde Tombaugh, after a year of searching at the Lowell Observatory, found Pluto passing through Gemini.

Thursday, February 6th. Written by Alan French.

The Sun set at 5:15. The Moon is now about 5 and half days old and is a pretty, fat crescent in the southwestern sky at 6:00 PM. The Moon will not set until 10:39, so this would be a good night for a little lunar observing.

A few features are visible to the unaided eye. Most obvious is the terminator, the line between the light and dark portions of the moon. Right now, this is the line that shows where sunrise is occurring on the moon. The terminator is creeping very slowly to the left across the face of the moon, but within the course of one night its progress usually goes unnoticed to the naked-eye observer. If, however, you look at the moon again tomorrow night, you should be able to see a noticeable shift of the terminator to the left from tonight's position.

It is also quite easy to notice distinct light and dark areas on the moon. The dark areas are called maria (MAR-ee-uh) which means "seas" in Latin. Galileo and other early astronomers assumed that the maria were bodies of water. We now realize that there is no water on the moon. The maria are actually dark and relatively smooth plains caused by ancient lava flows that spread over the floors of huge impact basins.

The bright patches on the moon show us areas where mountains and craters are found. Although these highlands make the moon appear quite brilliant, the moon's surface is actually rather dark. On the average, the moon only reflects about 7% of the sunlight that falls on it. This means that the moon's surface is approximately as dark as an asphalt parking lot.

When you turn a pair of binoculars toward the moon, the view is wonderfully improved. If you can support the binoculars steadily, a few dozen craters and mountain peaks become clearly visible. Details are most obvious along the terminator. Since that is the sunrise line, objects near it cast long shadows that make them stand out in bold relief.

With a telescope, changes are plainly visible in less than half an hour as the terminator proceeds in its slow march across the face of the moon. This ever-changing vista can give anyone with even the most modest equipment a lifetime of observing pleasure. Observing the moon with even a small telescope will reveal a wealth of detail, showing craters as small as four miles across.

Friday, February 7th to Sunday, February 9th. Written by George Mileski

Since time immemorial the moon has to be the object of fascination, awe, and admiration. This is not surprising as the moon is the brightest and most obvious celestial body aside from the sun. It is our closest neighbor in space. The moon's gravitational pull on one side of earth, causes the rhythmic ebb and flow of the ocean tides. The moon is 2160 miles across, about one quarter the diameter of earth and only a quarter million miles away. 

Each month as it circles around the earth the moon goes through a cycle of changes in its appearance called phases. Starting from "new moon", when it is nearly lined up between the sun and the earth, the moon progresses or waxes to a crescent, then to first quarter, when its half lit, then from first quarter to full moon, which is the gibbous phase. At full moon phase we see the entire face illuminated. Then the moon wanes back through gibbous, last quarter and crescent phases to new moon again. 

At every phase except full moon you'll notice that the lunar globe is divided by the terminator, the line separating the moon's bright sunlit side from the side hidden in shadow. Viewed in high-powered binoculars or a telescope the landscape near the terminator stands out in bold contrast and relief. The terrain looks very rough near the terminator, because here the sun shines low near the lunar horizon. Thus every surface feature casts a long black shadow that creates an exaggerated impression of height or depth.  

To the naked eye the most striking features on the moon's disk are its large irregular-shaped gray patches called "mare", which means "sea". Early telescope users thought these dark markings were similar to earth's bodies of water. The maria are in fact great lava flows that filled much of the lunar lowlands billions of years ago. This weekend is a good time to study the moon, Sunday it is at first quarter.    

Monday, February 10th. Written by Joseph Slomka.

The Sun sets at 5:20 tonight, with night falling at 6:55. Dawn breaks at 5:23 tomorrow morning, and ends with sunrise at 6:58.

As the sky darkens, the nine day old Moon becomes readily apparent. In a short time, Saturn appears to the Moon's lower right, in the constellation Taurus. Finally, Jupiter glows low on the eastern horizon.

By sunrise, three bright planets appear in the southeast. Venus is the brightest by far. In powerful binoculars, it appears as a large crescent, about two-thirds illuminated. Mars shines more dimly to Venus' right. While Mars seems small and dim now, it grows brighter and larger daily; by summer it will be a showpiece. Mercury shines brightly, but close to the horizon on Venus' lower left. If you do spot Mercury, powerful binoculars or telescopes show it as a slightly fatter crescent than Venus.

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 short-wave radio and directional antenna, you can hear the static these storms generate.

A complex satellite system is Jupiter's other attraction. There are thirty-nine moons, of which four are visible to small telescopes and binoculars; Jupiter now replaces Saturn as the planet with the most moons. Io is a forbidding place where volcanoes spew sulfur and the surface is stained various colors. While Europa is a frozen wasteland; ice, many feet thick, covers most of the planet. If you have a telescope or powerful binoculars, you can witness moons of Jupiter eclipsing each other. Starting at 9:28 and ending 10:25 this evening, Io and Ganymede undergo a series of mutual eclipses. This is a chance for you to recreate Galileo's discovery and wonder at the dance of these four moons.

Tuesday, February 11th. Written by Jonathan Cassidy.

The waxing gibbous moon wipes out most of the dim stars tonight. Fortunately we have bright planets to find, but how do we know the planets from the stars with out a telescope?

Early astronomers knew the planets due to their name "Planet" is the Greek word for "Wondered". Thus if we watch night after night we can chart the heavenly bodies that "wonder" across the sky. Notice first the bright circle of stars each clear night. These are (from farthest south going clock wise): Sirius, Procyon, Pollux, Castor, Capella, Aldebaran, Rigel and back to Sirius. Notice that there are many other bright lights and this might confuse you.

Capella is the only bright star near the zenith or top of the sky. Go directly south from Capella one full hand span and you will find a line of bright objects: The moon is the most obvious slightly to the west of the zenith. Moving to the east you will find Aldebaran, Saturn, Pollux and Castor and finally Jupiter.

A rough chart of these on a weekly basis will show that the Moon, Jupiter and Saturn move the most, while the stars seem to keep the same relative distance with each other. Do not be confuse if Jupiter and Saturn seem to be going backwards at this time. Each planet undergoes retrograde as we pass them in our quicker orbit.

Wednesday, February 12th. Written by Ray Bogucki.

Our three, fellow, rocky, inner planets are all currently visible in the early morning sky. Mars rises first, in the Southeast, about 3 a.m., in a dark sky. At 4:30, Venus appears, rising in the East-southeast while the sky is still dark. After the first hint of morning twilight, Mercury follows Venus, rising about 6 a.m. Mercury and Venus overtook and passed Earth some time ago in their faster, inside orbital lanes and are now leaving us in their interplanetary dust. By mid-March, Mercury, the speediest planet, will swing behind the Sun and be lost from view. Venus is heading the same directtion, but at a slower pace. Mars, in the next orbit outside Earth's, moves slower than we do and we are in the process of overtaking the Red Planet. We are drawing closer to Mars by nearly a million miles each day, while Venus recedes by about 650 thousand miles daily. The behavior of these two nearest planetary neighbors over the next few months provides an elegant demonstration of the results of our clockwork orbital motions.

As Venus recedes, its disk size in a telescope, currently 18 arc-seconds, will slowly diminish while Mars' disk, currently about 5 arc-seconds, will grow. In May, the two planets will appear equal in size, at about 10 arc-seconds. By July, Mars will be twice the size of Venus. During this process, Venus will diminish a bit in brightness while Mars will brighten noticeably from week to week. In the sky, Venus will rise closer to the Sun each week, while Mars continues to rise earlier. By June, Mars will rise at midnight while Venus will be rising in bright morning twilight. Late next August, just as Venus finally slides behind the Sun, Mars, now ballooned to a massive 25 arc-seconds, will be rising majestically in the East at sunset, gleaming at a brilliant magnitude of almost minus 3, outshining every object in the night sky other than the Moon and providing astronomers with the best observational opportunities in many years. Our ability to predict these behaviors with such admirable accuracy is a tribute to the quiet Polish monk, Copernicus, who, in 1543, published his revolutionary book "De Revolutionibus," which first taught the world how the motions of planets and moons really work.

Thursday, February 13th. Written by Alan French.

The International Space Station will be visible from our area early this evening. It will appear above the west-northwestern horizon at 6:20 PM, although you may have to wait another minute for it to rise higher above the horizon and brighten. The ISS will be highest at 6:23 PM when it will be 43 degrees above the southwestern horizon, and will vanish in the south-southeast at 6:26 PM. You will probably find the Space Station easiest to spot when it is highest. Simply look for a fairly bright star moving through the southwestern sky toward the south-southeast.

The ISS is visible because it is still up in the sunlight while we are down in the Earth's shadow. As you watch the ISS pass silently among the stars consider that there are three residents perhaps gazing down at the Earth below.

An attentive sky watcher will usually spot a few satellites crossing the sky during the hours just after sunset or just before sunrise. You can get satellite predictions tailored to your location at www.heavens-above.com.

If you look toward the East tonight around 7:00 PM, you will see a bright Moon, now a bit over three days before Full Moon. Tonight the Moon is near Castor and Pollux &endash; the two brightest stars to the left of the Moon at 7:00 PM. Castor and Pollux are the two brightest stars in the constellation of Gemini, the Twins. Castor is the highest of the pair while Pollux is the brightest of the pair.

Twins Castor and Pollux were considered protectors of sailors. Pollux was immortal but Castor was not. When Castor was killed, Pollux was allowed to join him in the sky, following his twin brother across the sky.

The two stars mark the heads of the twins. The stars marking the rest of the constellation form an obvious rectangle. The long sides of the rectangle form the bodies of Castor and Pollux.

If you follow the Moon over the next three nights, you can easily see its eastward motion among the stars. Tomorrow night it will be below Castor and Pollux, and on Saturday night, it will be down below Jupiter. The Moon and this brilliant planet will be a pretty sight in the early evening sky then.

Friday, February 14th to Sunday, February 16th. Written by George Mileski

The moon on Friday February 14th is a waxing gibbous one, reaching full moon on Sunday the 16th. On Saturday Jupiter is 4 degrees south of the moon. Look for the beehive star cluster located several degrees above Jupiter. The beehive or in latin "praesepe" is one of the harbingers of spring. The Messier number is M44. M44 is easy to find even if Jupiter isn't there to guide you. 

It appears as a cloudy patch of light about twice the size of the full moon, in the constellation of Cancer the crab. Since Cancer is such a faint constellation to begin with, look for M44 as a cloudy area about midway between Leo and Gemini. The reason the beehive looks cloudy is that its brightest star, epsilion cancri, glows faintly at magnitude 6.3. Meanwhile 14 other members in the cluster have magnitudes brighter than 7.5. Many observers can't see a star of magnitude 6.3 without optical aid.  So, most people perceive the light from all the stars in the cluster as a hazy patch of light whose equivalent magnitude is 3.1. 

The fuzzy, naked-eye visibility of the beehive cluster has served as a weather forcasting tool since ancient times. The Greeks held that if praesepe was obscured by mist, bad weather would usually follow. We now know that cirrus clouds obscure objects like the beehive and are indeed harbingers of rain. 

Present-day studies show there are more than 300 stars in the cluster. We also have deduced that the beehive is 520 light-years away and about a dozen light-years across. That places it as one of the nearest open clusters to earth. Because of its proximity to earth, the beehive is magnificent in binoculars and looks even better in a low-power telescope having a field of 2 or 3 degrees. Its also one of the easiest clusters to photograph with moderate telephoto lenses.  

Monday, February 17th. Written by Joseph Slomka.

Tuesday, February 18th. Written by Jonathan Cassidy.

The near full moon, this evening, rises about 7:47 PM. This large moon washes out all but the brightest stars.

The stars we need to know this season are: Aldebaran, Rigel, Sirius, Procyon, Pollux, Castor and Capella. These stars can be found in a circle around the red star Betelgeuse. Do not confuse Saturn and Jupiter for stars. These planets are the brightest of all the star like lights in the sky tonight and are found along the path of the sun called the ecliptic. They will be seen to move against the background of stars from night to night.

Of the true stars Aldebaran is furthest to the west, near the top of the sky and on the red/orange in its color.

Rigel is south of Aldebaran.
Sirius is south east of Rigel.
Procyon is north east of Sirius.
Pollux and Castor line up with Procyon along a line that will take you to Polaris the North star.
Capella is the bright star nearest to the top of the sky.

Betelgeuse, Pollux, and Aldebaran are all red stars. To the eye they will look to have a slight orange cast to the color. The star Betelgeus is so large that if it were at the center of our solar system it's outer edge would be near the orbit of Jupiter.

Wednesday, February 19th. Written by Ray Bogucki.

Thursday, February 20th. Written by Alan French.

Friday, February 21st to Sunday, February 23rd. Written by George Mileski

As our planet travels around the sun every year, it meets up with large amounts of dust, usually tiny particles that are no bigger than a grain of sand. These pieces of dust are called meteoroids. The fast movement of the particle through the atmosphere causes the surrounding air to glow brightly. Meteors are glowing particles traveling through our earth's atmosphere. 

Observing meteors is easy and fun. It does not require binoculars or a telescope or any special equipment. No I take that back, it does require special equipment, a lawn chair. However, you do concentrate on a certain area of the sky for up to an hour at a time, in order to get a good idea of the number of meteors flashing through the atmosphere. In this way meteor observing can be challenging. It will also help an observer to become more familiar with the sky and the constellations. 

Meteors can appear on any night of the year, but they are much more common at certain times of the year. Meteors are most common on certain special "shower" nights during the year, when earth encounters a stream of meteoroids of dust particles. Most of the "shower" meteors appear to come from a single location in the sky. We say that they are "radiating" from that point in the sky, and that point is called the "radiant".   

It is possible to see bright meteors that are brilliant enough to cast a shadow on the ground. These are called fireballs or bolides, especially if they appear to break up into several pieces. Sometimes they even appear to explode into several fragments. Occasionally, too, they appear to glow in different colors, such as green or red.  

The next meteor shower is in April, it is called the Lyrids. Its one of the minor showers of the year, it occurs about April 22nd. 

Monday, February 24th. Written by Joseph Slomka.

The Sun sets at 5:38 PM, with night falling at 7:12. Dawn breaks at 5:04 AM, and ends with sunrise at 6:38.

As the sky darkens, three lights shine brightly. Jupiter, first and brightest, is moderately high in the East. Sirius lies low in the southeast, while Saturn is last to appear high in the South. As twilight ends, an observer finds Jupiter in Cancer, a dim constellation. In binoculars, one can not only see the moons of Jupiter, but also the Beehive star cluster only three degrees away.

Saturn lies in Taurus, amid the Bull's horns. M-35, a bright and dense star cluster lies not that far away. A bit below Saturn is the constellation Gemini. If you have dark skies, a hazy patch is found by the northern foot. This is M-35, another grand binocular object. Saturn is also on the move. Note its position. After moving westward for a few months, it stopped and now is proceeding eastward.

Dawn finds Mars, the Moon and Venus in the southeast. Mars is highest but quite dim. Our Moon is past Last Quarter and only about a third illuminated. Finally, Venus lies quite low near the horizon. In fact, trees and hills may hide it, until just before sunrise. By then, Venus is quite brilliant and obvious while Mercury replaces it as the low object near the horizon.

Cancer is famous for galactic clusters. Although visible to the naked eye on moonless nights, M44, also known as "Praesepe," "Beehive" or "Manger" requires binoculars to fully appreciate its beauty. The stars do resemble a swarm; about 200 stars are members of this group. The "Beehive" is about 40 light years in diameter, 525 light years distant and occupies about 1 degree of sky. The Greeks used it as a weather forecasting tool; high altitude haze would obscure this nebula, a prediction for stormy weather. The ancients called the Praesepe a "little cloud," since they could not see individual stars. Leonardo Da Vinci was the first to train a telescope on this "cloud" and realized its true nature.

Tuesday, February 25th. Written by Jonathan Cassidy.

Dark nights this week as the waning crescent rises well after midnight. Tonight we can look for dim objects in the night sky. The most famous deep sky object out tonight is the Orion Nebula. This star formation region is visible to the naked eye even under city lights.

Nearly due south, and half way up the sky, most people will find the familiar three stars of the belt of Orion. Go south from these stars and find a line of three points dimmer than the belt stars. Notice that one or two of them are not points of lights like the stars. Indeed the middle one is rather fuzzy.

This is the Orion Nebula. It is a star formation region. It has gasses being compacted and falling in on themselves due to external pressures and their own gravity. The brightest stars of this region are a compact set known as the "Trapezium". These can be seen with binoculars as the brightest spot in the nebula. With most telescopes on a steady mount you can see the four brightest stars. More aperture and heavier mounts reveal two additional stars.

More interesting is that the clouds of gas hide many more stars and proto stars. The gas around them is still being collected by the star's gravity or is just beginning to be blown outward. Stars do not blow away the surrounding gas till they start their nuclear furnaces. This does not happen if the star is too small. Some times near by stars will blow away the available star making gasses before some of the bodies get large enough to burn.

Wednesday, February 26th. Written by Michael Molitor.

We are approaching new moon, so the sky is moon-free most of the night. Saturn and Jupiter are the two planets well placed for evening viewing. Zero magnitude Saturn is in Taurus high in the southwest, while Jupiter is in Cancer high in the southeast at magnitude minus 2.5. Jupiter’s great red spot will transit the giant planet’s central meridian around 7:30 pm this evening.

The zodiacal light is the very faint glow from sunlight reflecting off myriad dust particles in the Earth’s orbit. From mid-northern latitudes, certain times of the year are more favorable for viewing the zodiacal light than others. When the ecliptic makes a steep angle to the horizon such as in late winter and early spring the zodiacal light is best sighted in the evening. Early autumn provides the best pre-dawn viewing. The phenomenon is faint, like the Milky Way, so the atmosphere must be clear and the sky moonless, and you must be far from city lights. If atmospheric conditions are favorable, look for it in the west tonight around 7:15 pm. The zodiacal light will form a ghostly white triangular shaped glow with its base on the western horizon, and its axis stretching along the ecliptic toward Saturn.

The predawn sky will find a thin crescent Moon, 13% illuminated, rising at 5:01 am Thursday. The planet Venus, striking at magnitude minus 4.1, will be 6-degrees to the upper left of the Moon. Through a small telescope, Venus shows phases just like the Moon. Venus is headed toward superior conjunction with the Sun later this summer, and is presently 70% illuminated and waxing gibbous. Mars, at magnitude +1.0, is 25 degrees to the right and some 18 degrees above the Moon. Mars is headed toward opposition with the Sun in August, so look forward to good views of the red planet late this summer.

Thursday, February 27th. Written by Alan French.

Friday, February 28th to Sunday, March 2nd. Written by George Mileski

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