A Black Moon, Bright Mars and the Paradoxical Winter Solstice

By Matthew M. Johnson

As December unfolds, the nights grow longer and reach a maximum on Dec. 21, the day of the winter solstice, when the sun rises at 7:10 a.m. and sets at 4:15 p.m. This affords us only nine hours and five minutes of daylight and a long 14 hours and 55 minutes of darkness. Besides being one of the longest nights of the year and marking the change in astronomical seasons from fall to winter, the winter solstice paradoxically begins a return of the sun. We begin gaining about four minutes each day. This continues until the summer solstice in June.

Planets 
Look to the southwest on Dec. 2- 5 to view a crescent moon approaching a brilliant Venus about 45 minutes after sunset. On Dec. 7, look to the southwest about an hour after sunset to view the moon next to the planet Saturn. About 40 minutes after sunset on Dec. 13, a large moon will be visible just under the Pleiades star cluster in Taurus. The next day, a nearly full moon will be to the left of Jupiter. On Dec. 28, look to the southeast 30 minutes before sunrise to view a tiny crescent moon to the right of Antares, the red giant star in the constellation Scorpio. Mercury can be located just to the left of this crescent moon. 

At dusk on Jan. 1, a crescent moon looms low on the horizon, with Venus to the left and Saturn between them. On Jan. 10, the moon is next to Jupiter. On Jan 13, around 7:30 or 8 p.m., the moon will eclipse the red planet Mars and will reappear about an hour later. This is a rare event. Mars is especially worth viewing around 7:30 p.m. on Jan. 15 when it is directly opposite the sun and close to Earth in its orbit. Mars will not be this bright again until 2031.

Meteor Showers 
There are two major meteor showers in December. The Geminid shower, which occurs Dec. 4- 17 and peaks Dec. 13-14, and the Ursid meteor shower, which occurs from Dec. 17- 26 and peaks on Dec. 22. The Geminid shower is one of the best of the year, with rates up to 130 to 140 per hour. Unlike meteor showers caused by the passing of comets, the Geminids are the result of the asteroid Phaethon leaving debris in its orbit around the sun. The Ursid shower is associated with Comet 8P/Tuttle which orbits every 13.5 years. 

The Quadrantid meteor shower occurs Dec. 28 to Jan. 12, 2025, with a peak on Jan. 3. The Quadrantid shower is thought to be caused by dust and debris left in the inner solar system by the asteroid 2003 EH1, which orbits the sun every 5.5 years. 

Moon Phases 
Dec. 1: New moon (no visible moon). The best time to observe faint objects such as distant galaxies. 
Dec. 8: First quarter (right half of moon illuminated). Moon is waxing.
Dec. 15: Full or Cold Moon.
Dec. 22: Last quarter (left half of the moon illuminated). Moon is waning. 
Dec. 30: Last quarter (no visible moon). The best time to observe faint objects such as distant galaxies.
Jan. 6: First quarter (right half of moon illuminated). Moon is waxing.
Jan. 13: Full or Wolf Moon.
Jan 21: Last quarter (left half of the moon illuminated). Moon is waning. 
Jan 29: New moon (no visible moon). The best time of the month to observe faint objects. 

December has two new moons, a phenomenon called a black moon. This is as rare as when a month has two full moons; in this case the second full moon is termed a blue moon. It takes 29.5 days to go from new moon to new moon. 

December’s full moon was known by Native Americans as the Cold Moon because it is when the winter air settles in, and the nights become long and dark. This moon has also been known as the Long Nights Moon because it is close to the winter solstice.
January’s full moon was known by Native Americans as the Wolf Moon because wolves were more likely to be heard calling at this time. The Assiniboine people of the Northern Great Plains called January’s full moon the Center Moon because it marked the middle of their coldest season, while the Algonquian people knew it as the Freeze Up Moon and the Dakota knew it as the Hard Moon, referring to the snow crust. 

Notes
The winter solstice marks the beginning of winter in the northern hemisphere and the first day of summer in the southern hemisphere. The North Pole is tilted to its greatest extent away from the sun while the South Pole is tilted to its greatest extent toward it. In our hemisphere, the sun’s rays are mostly shining below the equator and are centered directly over the Tropic of Capricorn at 23.44 degrees south latitude. During this time, the North Pole experiences 24 hours of darkness and the South Pole 24 hours of daylight. The word solstice is from the Latin sol (sun) and sistere (to not move), meaning sun stands still in winter.

I am conducting physical measurements of the local level of darkness using a portable photometer at many locations in Norfolk, Canaan and Colebrook. I will share this information with professional databases that use it to determine current values as well as changes in the levels of light pollution in our skies. Norfolk has some of the darkest skies in Connecticut.