What’s Up in the December Sky
December’s Evening Planets
Find bright Jupiter and Saturn between Sagittarius the Archer and Capricornus the Sea-goat until around 8 p.m. and setting earlier every night until 6 p.m. by the end of the month. On December 21st Jupiter and Saturn will look at their closest point of their conjunction forming a bright double planet. Red Mars will be in Aquarius the Water Bearer all night. Uranus will be in Cetus the Sea monster and Neptune in Aquarius the Water Bearer.
December’s Evening Stars
Spot the Summer Triangle of Vega in Lyra the Harp; Deneb in Cygnus the Swan; and Altair in Aquila the Eagle, until 9 p.m., setting earlier every night. The Winter Triangle of Sirius (the brightest star viewed from Earth) in Canis Major the Great Dog; Betelgeuse in Orion the Hunter; and Procyon in Canis Minor the Small Dog, will be up as of 9 p.m. Find Castor and Pollux in Gemini the Twins, Rigel in Orion, Aldebaran in Taurus the Bull, and bright Capella in Auriga the Charioteer. See the stars of constellations Andromeda, Cassiopeia, Perseus, Cepheus, Draco, Aries, Taurus, Pegasus, and Ursa Major and Ursa Minor (the Big and Little Dippers).
December’s Morning Planets
Bright Venus will be up from around 5 a.m. until sunrise, moving between Libra the Scales and Scorpio the Scorpion throughout the month. Mercury could be seen moving between Libra the Scales and Scorpio the Scorpion as of 6 a.m. in the first week of December. Uranus will be in Cetus the Sea Monster until 4 a.m., setting earlier each night until 2 a.m. by the end of the month.
December’s Morning Stars
The Winter Triangle of Sirius, Betelgeuse, and Procyon will be up until morning. Find Capella in Auriga, Arcturus in Boötes the Herdsman, Spica in Virgo, and Aldebaran in Taurus until the morning. See the stars of Leo, Gemini, Orion, Hydra, Hercules, Cassiopeia, Cepheus, Draco, Perseus, and Ursa Major and Ursa Minor (the Big and Little Dippers).
- Dec. 7: Last quarter Moon at 7:35 p.m.
- Dec. 12: Moon at perigee (224,800 miles away)
- Dec. 14: Geminids Meteor Shower peaks— predawn
- Dec. 14: New Moon at 11:15 a.m.
- Dec. 21: Winter solstice at 5:00 a.m.
- Dec. 21: First quarter Moon at 6:40 p.m.
- Dec. 21: Jupiter and Saturn conjunction closest approach, closest approach viewed from Earth since 1226— sunset
- Dec. 24: Moon at apogee (251,700 miles away)
- Dec. 29: Full Moon at 10:28 p.m.
Times given in EST.
Download Ken Graun’s December 2020 sky chart for reference and observing ideas.
Another equally helpful resource is Skymaps monthly evening sky charts available for different hemispheres. Download The Evening Sky Map for December.