Last modified: Tuesday, December 3, 2002
STAR TRAK/December 2002
Saturn at its best offsets the Geminid meteors
Saturn will be visible all night during December, rising in the east at dusk and setting in the west at dawn. On the night of Dec. 16-17, Saturn will be opposite the sun in our sky, so it will be at its closest, biggest and brightest for the year.
What makes this opposition special is that the planet will be at its best in 30 years, because of the tilt of its rings toward Earth and its nearness to the sun in its orbit. This month and December 2003 will be the finest opportunities in decades for viewing Saturn and its rings with a telescope. The bright yellow planet will be highest in the south around midnight local time.
Jupiter will be next to appear, rising after 10 p.m. local time at the beginning of the month and two hours earlier by month's end. Jupiter will be at opposition in February, and already it appears unusually big and bright, easily outshining Saturn at its best. The two huge planets will be separated by the constellation Gemini with its stars Castor and Pollux. Below them will be the constellation Orion the Hunter with its collection of bright stars. The combination of all of these brilliant objects will be a lovely sight as it crosses the night sky.
Then Venus will upstage all of them, rising with Mars in the east-southeast about three hours before sunrise at the beginning of December and an hour earlier by the end of the month. Venus and Mars will be close companions all month, accompanied by the bright white star Spica on the right (south) in the constellation Virgo the Maiden. The faint orange of Mars will seem almost inappropriate as it performs a slow dance with gorgeous white Venus, the brightest object in the night sky after the moon. It is rare for two planets to remain so close for so long without either one passing the other.
Mercury will be visible with binoculars low in the southwest after sunset in the second half of December. It will reach its greatest distance above the horizon on Dec. 25, setting about 90 minutes after the sun.
The Geminid meteor shower will peak on Dec. 14 at about 4 a.m. EST. The first-quarter moon may obscure some of the bright streaks crossing the sky.
Normally the Geminid shower is the best of the year. In a clear sky away from city lights, observers can expect to see about 80 meteors per hour at the peak. Meteors or "shooting stars" will be visible from late evening until the peak before the start of morning twilight. They will seem to be coming from a point (the radiant) near the bright stars Castor and Pollux in the constellation Gemini the Twins, which gives the shower its name.
The radiant will be well above the eastern horizon a few hours after sundown and will remain high in the sky the rest of the night. Try facing southeast toward the radiant, though meteors will be visible in all parts of the sky.
On Dec. 4, a total solar eclipse will be visible in a narrow path that will begin in the South Atlantic, cross southern Africa and the Indian Ocean, and end at sunset in southern Australia. The eclipse will be Webcast live from Australia at http://www.csiro.au/helix/eclipse/.
A partial eclipse will be seen in most of Africa, western Australia and Antarctica. Details are available at http://sunearth.gsfc.nasa.gov/eclipse/TSE2002/TSE2002.html.
An excellent source of information about all eclipses is provided by the National Aeronautics and Space Administration at http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html. It includes detailed maps and tables showing the starting and finishing times of every eclipse for many cities.
A safe way to view an eclipse is through a piece of No. 14 welder's glass, which can be bought for a few dollars at a welding supply store. It will block all of the sun's infrared and ultraviolet radiation and most of the visible light.
The eclipse can be viewed indirectly by poking a hole in a piece of cardboard with a slender pin and letting sunlight come through the hole onto a piece of white paper held a couple of feet away. The smaller the hole, the sharper the sun's image on the paper will be. Move the paper forward and back until the image of the sun is focused as much as possible.
The sun will reach its southernmost point in the sky, called the December solstice, on Dec. 21 at 8:14 p.m. EST (1:14 Universal Time on Dec. 22). This will mark the start of winter in the Northern Hemisphere and summer in the Southern Hemisphere. For the next six months in the Northern Hemisphere, the days will be getting longer.
The moon will be new on Dec. 4, at first quarter on Dec. 11, full on Dec. 19 and at third quarter on Dec. 27.