December 2002

By Steve Stefanik

"On the first day of Christmas my true love gave to me . . . an opposition of Saturn, the rising of Jupiter, a conjunction of Venus, an apparition of Mercury, a meteor shower, a winter solstice . . . and a partridge in a pear tree."

As the month of December begins, the sun is setting earlier and earlier as it heads toward the Winter Solstice, which will occur on the 21^st at 8:14 p.m. EST, when we will have the least number of daylight hours during the year on that day. The sun will appear to set the farthest south on the western horizon that evening but begin its northerly trek once again on the following day.

Take advantage of the earlier evenings and longer nights to get out under the stars and have a look around. Start by looking for the two most distant giant planets, Neptune and Uranus, low in the southwest among the stars of the constellation Capricorn. Neptune is the more difficult of the pair to spot because it is the dimmer of the two at +8.0 magnitude and closest to the horizon in western Capricorn. You’ll need binoculars or a telescope to spot it. Uranus on the other hand is considerably higher above the horizon and brighter at +5.4 magnitude. You may be able to spot it with just your eyes if you are away from city lights.

Around the time Uranus is setting (9:00 p.m. EST), do an "about face" and look toward the northeastern horizon. You will see the familiar "V" of the constellation Taurus the bull with the small blue white cluster of stars called the Pleiades above it. If you look to the left and above the outstretched arm of Orion the hunter, you should see a bright –0.5 magnitude yellow-orange "star" at the feet of the constellation Gemini the twins. This is the planet Saturn. Through binoculars or a telescope you will see its breathtaking "rings". This year the rings are tipped as much as they ever are and it will be as close to the sun as it ever gets in its 30-year orbit. When it reaches opposition (directly opposite the sun from earth) on the 17^th of this month it will appear as big and as bright as it ever gets. If you’ve never seen it "up-close", now is the time.

If you are out looking at Saturn, you may notice a considerable number of "shooting stars" or meteors as they are called, emanating from Gemini. As we approach the night of the 13/14^th as many as 80 meteors per hour may be seen at the peak of this year’s Geminid meteor shower.

If you are still out and about around 10:00 p.m. you may notice an even bigger and brighter "star" rising lower and to the left of Gemini among the stars of the constellation Leo the lion (which looks like a huge backwards question mark). This is the –2.4 magnitude giant planet Jupiter. Through binoculars or a telescope you can see its four Galilean moons encircling it as well as its alternating light and dark bands of clouds. You may also catch a glimpse of its "Great Red Spot" in its southern hemisphere if the timing is right.

The planets Venus and Mars rise about 3 hours before sunup in the east. Venus is a spectacular –4.7 magnitude marvel while Mars is a mere +1.5 magnitude meanderer in contrast but the pair will be in conjunction hovering within 2 degrees of one another the first two weeks of the month. A crescent moon joins the pair tonight and again on the 30^th of the month making a magnificent memorable montage.

The planet Mercury makes an appearance the last two weeks of the month low in the southwest as the sun sets. This speedy little –0.5 magnitude planet reaches its greatest elongation from the sun and appears at its highest above the western horizon on the evening of December 25^th , giving you and your kids a chance to try out that new telescope you got for Christmas.