Christmas Comet, Winter Solstice, 4-Day Full Moon and More Dec Events


December 2021 offers the best chance to see a newly discovered Christmas comet that won’t return for 80,000 years, plus, the longest full moon of the year lasts 4 days, the winter solstice and more December weather events.

Christmas comet this week won’t return for 80,000 years

This week will provide the best chance to see a “Christmas comet” that won’t make its way back for 80,000 years.

Comet Leonard, a.k.a. Comet C/2021 A1, only discovered earlier this year, will make its closest approach to Earth on December 12, and will also be more prominent in the evening sky for several days thereafter, AccuWeather reports.

One of the best viewing opportunities came Friday, December 17, when the comet appeared directly below Venus after sunset. This week, the comet will, little by little, shift to the left of Venus as we move toward Christmas.

Using a telescope or binoculars, the comet will appear as a fuzzy green star with a small tail. A representative for NASA said the comet will not be as bright as last year’s comet NEOWISE.

December’s 4-day “cold moon” is the longest and last full moon of the year

The moon will appear full over the course of four days in December. Although the moon began to appear as full on Friday night Dec. 17, it officially achieved that status on Saturday night Dec. 18, when the last full moon of the year occurs before the winter solstice in the northern hemisphere, reports. It will also be the longest full moon of the year that peaked on Sunday night, Dec. 19 at 11:36 PM EST. But wait, there’s more… The moon will still appear full all the way through Monday morning December 20, with NASA dubbing it “a full moon weekend.”

December moon is a “Micromoon”

The opposite of a Supermoon, when the moon appears larger because of its nearer proximity to earth, a Micromoon is exactly how it sounds, when the full moon is at its farthest point from Earth. In astronomical terms, it is referred to as an Apogee. In December 2021, the moon will be approximately 252,000 miles from earth.

Full cold moon

The name “cold moon” for December’s full moon comes from Native American, colonial American, and other traditional sources, according to the Old Farmer’s Almanac. Specifically, “cold moon” comes from the Mohawk tribe, referring to when cold weather began its first firm grip in the winter season.

Shortest day of the year: Winter solstice arrives on Tuesday, December 21

For Earth’s Northern Hemisphere, on Tuesday, December 21 at precisely 10:59 AM EST, the North Pole will make its farthest tilt – 23.5 degrees away from the sun. The event is also the “shortest day” of the year, offering the fewest hours of sunlight – 8 hours in 46 minutes, according to Past this date, the amount of sunlight will slowly increase until the spring equinox which will bring equal hours of day and night, which occurs on Sunday, March 20, 2022.