By Matthew Johnson

Sunrise on Dec. 1 is at 6:57 a.m. and sunset at 4:21 p.m., and the nights will continue to grow longer as December progresses, reaching a maximum of 14 hours, 51 minutes, 28 seconds on the successive nights of Dec. 21 and 22. By month’s end, though, we will have gained back 3 minutes, 11 seconds of daylight.

During the December long nights, we will have wonderful viewing of the naked-eye planets. As Earth proceeds in its orbit around the sun through the winter months, however, the planets will move into more difficult viewing positions. 

Several conjunctions, or moments when two or more planets are grouped together, will occur this month. On Dec. 1, Venus, Saturn and the crescent moon will be low in the western sky just after twilight, with Jupiter floating above them. Venus will meet Saturn on Dec. 11.

Learning to recognize the planets as they wander among the myriads of background stars is best done on nights when the planets are in conjunction. When they are near the moon, it is easy to locate them and make a positive identification. And when they are grouped, you can compare the nuances of color and brightness between the planets. The opportunity is all the more to be seized when the conjunction occurs early in the evening, as this one does.

Though it seems counterintuitive, Earth is actually closer to the sun during December and January than it is during the summer months. It is the tilt of Earth’s axis, tipping our Northern Hemisphere away from the sun that makes the cold months cold for us and angles the Southern Hemisphere toward the sun, making those months correspondingly warmer below the equator.

The winter solstice occurs on Dec. 21 at 11:19 p.m. This corresponds to the point in Earth’s orbit when the North Pole is at its maximum outward tilt. It is the day when, throughout the northern hemisphere, the sun rises from its southernmost point on the eastern horizon and climbs at noon to its lowest elevation in the sky, providing sunlight to Earth’s northern surfaces at the lowest angle and for the shortest length of time. The area above the Arctic Circle experiences 24 hours of darkness and the southern polar region 24 hours of daylight. After the solstice, the northern sun slowly rises higher each day and stays longer in the sky, until the summer solstice. 

The December full moon, known as the Cold Moon, will occur on Dec. 12 at 12:12 a.m. The Gemini meteor shower will be at its height the following night, Dec. 13, but the full moon will unfortunately interfere with viewing the meteor streaks.