Brilliant Jupiter, lording over the southern sky at nightfall, gets some competition this month from upstart Mars, ascending in the east. Mars and Earth will be at their closest in more than two years, making the Red Planet brighter than every star in the night sky.
On Dec. 7, the full moon will pass directly in front of Mars and cover it for up to an hour or more. The close pairing of two of the brightest night-sky objects should look amazing! From the Upper Midwest the occultation begins around 9 p.m.
The other sky highlight is the Geminid meteor shower, the richest of the year with up to 100 meteors per hour visible under ideal conditions. Although the waning gibbous moon will flood out the fainter shower members, it should still be a good show. Finally, the planet Venus returns to view low in the western sky at dusk at month’s end.
Wishing you merry nights under the stars and the pleasure of warming up indoors afterwords!
Events:
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Dec. 1 – Mars closest to the Earth for the year. We won’t be this buddy-buddy again until 2031. Shining at magnitude −1.8 in the constellation Taurus the Bull, the Red Planet is brighter than Sirius and nearly rivals Jupiter.
Dec. 7 – Full Cold Moon. The moon covers up the planet Mars for much of the U.S. and Canada except the Southeast and a chunk of the East Coast. No matter where you live, you'll still see a close conjunction of the pair. Start looking an hour or more before the occultation begins, so you can watch the two bodies slowly come together. The occultation occurs around 10-10:30 p.m. EST, 9-9:30 p.m. CST, 7-7:30 p.m. MST and 6-6:30 p.m. PST. I'll have more details in an upcoming post.
Dec. 8 – Mars is at opposition and lies directly opposite the sun in the sky. Rises around sunset and shines the entire night, setting at sunrise tomorrow.
Dec. 10 – Waning gibbous moon passes 2° south of Pollux, Gemini’s brightest star.

Dec. 13-14 – Peak of the annual Geminid meteor shower. Best after 10 p.m. through the early morning hours of Dec. 14. Typically, dozens of meteors per hour are visible streaming from the constellation Gemini. Dress warmly, use a reclining chair and face east or south.
Dec. 16 – Last quarter moon
Dec. 21 – Winter solstice. The first day of winter begins at 3:48 p.m. CST. Longest night and shortest day of the year.
Dec. 23 – New moon
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Dec. 26 – Waxing crescent moon passes a few degrees south of Saturn

Dec. 28 – Look for Venus about a half-hour to 40 minutes after sunset low in the southwestern sky. It’s in conjunction with Mercury this evening, with the fainter planet shining just above it.
Dec. 29 – First quarter moon