Mars rises in the east, as the sun is setting in the west — and you can find it loitering near the horns of the constellation Taurus the bull.
While Mars’s opposition officially occurs Dec. 8, you’ll see the Red Planet quite close to the moon on the evening of Dec. 7. The western United States will see the full moon occulting (blocking) Mars. The DC area will see Mars seeming to cling close to the moon.
Later in December, our favorite Red Planet loses a little brightness, dimming to -1.4 magnitude (bright) by the end of the month, according to the observatory.
On Dec. 1, find the first-quarter moon huddled nearby Jupiterwhich appears to hang out in the constellation Pisces in the southeastern sky after dusk. The large, gaseous planet is -2.6 magnitude, very bright. Catch Jupiter every month. The fattening moon also approaches Jupiter on Dec. 28, passing the planet by Dec. 29.
As the sky darkens after dusk, find Saturn in the south-southwest preparing to set. The ringed planet stands at the constellation Capricornus at +0.7 magnitude, a little faint under urban conditions.
By the middle of December, catch the playful pals Mercury and Venus in the southwestern sky as dusk turns to night. They are very low on the horizon. The fleet Mercury will be harder to see at -0.6 magnitude (bright), but Venus will be brilliant at -3.9 magnitude (exceptionally bright). Venus has been hiding near the sun since October and will climb the evening heavens in January.
The Geminid meteor shower peaks Dec. 13-14, and astronomers estimate 150 an hour late into the evening, according to the American Meteor Society (amsmeteors.org). You won’t see all of them, but if the skies are clear and you avoid streetlights, you can catch several. A waning gibbous moon rises before 10 pm, and it may wash out some meteors.
Autumn yields to winter, as in December solstice ushers the change of season on Dec. 21, according to the observatory. On that date, Washington officially gets 9 hours 26 minutes of daylight, according to the observatory, creating what is called the shortest day of the year. We’ll see a smidgen more sunlight the following day.
* Dec. 2 — “The Latest on the Great Dinosaur Extinction,” a lecture by Sean Gulick, a research professor at the University of Texas at Austin. Catch up on how an asteroid impact killed off dinosaurs. Hosted by PSW Science. 8 pm, Powell Auditorium at the Cosmos Club, 2121 Massachusetts Ave. NW in DC Information: pswscience.org.
* Dec. 4 — See late autumn’s starry skies through telescopes provided by members of the Northern Virginia Astronomy Club (NOVAC). At the National Air and Space Museum’s Steven F. Udvar-Hazy Center, Chantilly, Va. (GPS: 14390 Air and Space Museum Parkway.) Meet at the museum’s bus parking lot, 5-7 pm Information: airandspace.si.edu.
* Dec. 10 — The latest discoveries by the Atacama Large Millimeter Array (Chile) and the James Webb Space Telescope, a talk by astrophysicist Joe Pesce of the National Science Foundation. At the regular meeting (online only) of the National Capital Astronomers. 7:30 pm For access, visit: capitalastronomers.org.
* Dec. 11 — “Tick, Tick, Tick: Pulsating Star, How We Wonder What You Are,” a lecture by the astrophysicist Jocelyn Bell Burnell, who discovered the first radio pulsar in 1967. While Burnell will lecture virtually, members and guests are welcome in person at the Northern Virginia Astronomy Club meeting, Room 3301, Exploratory Hall, George Mason University in Fairfax, Va. 1:30-3:30 pm Info: novac.com.
* Dec. 16 — “Back to the Moon to Stay: Lunar Surface Innovation Consortium,” a lecture by the planetary geologist Brett Denevi and the physicist Wesley Fuhrman, both from the Applied Physics Laboratory at Johns Hopkins University. Hosted by PSW Science. 8 pm, Powell Auditorium at the Cosmos Club, 2121 Massachusetts Ave. NW in DC Information: pswscience.org.
* Dec. 17 — “Astronomy for Everyone” at Sky Meadows State Park in Fauquier County, Va., with members of the Northern Virginia Astronomy Club guiding you through the sky. 4:30-7:30 pm GPS: 11012 Edmonds Lane, Delaplane, Va., 20144. Info: Novac.com. Park fee: $10.