The Cold Moon will rise high in the Boise sky on Wednesday night, illuminating the city in its chilly glow for over 15 hours.
No, the moon isn’t especially chilly this time of the year, nor is it making it any colder down on Earth. But it is the last full moon of 2022 and has a higher trajectory than most other full moons, meaning it’ll stay in the sky longer than usual.
As an added bonus, this year’s Cold Moon will fully occult the planet Mars as the moon’s path crosses Mars and completely obscures it from view.
Here’s what you need to know about Cold Moons, what makes them unique, and the exact time this year’s Cold Moon will appear in Boise.
When can I see the Cold Moon?
Although this year’s Cold Moon will reach peak illumination at 9:09 p.m. on Wednesday, according to the Farmers’ Almanac, you don’t have to wait until then to see the natural phenomenon. Like any other full moon, the Cold Moon is visible from around sunset until sunrise.
The moon should start to peek over the horizon just before sunset, according to the Farmers’ Almanac. In Boise, the moon will rise at 4:40 p.m. and set at 7:49 a.m. on Thursday.
Although some clouds are forecast for the Boise area, National Weather Service meteorologist Bill Wojcik told the Idaho Statesman that the moon shouldn’t be obscured from view.
“It looks like this lower stratus (cloud layer) caused by the inversion we’ve been dealing with is mixing out,” Wojcik said. “We don’t think it’ll fill back in with the stratus tonight in the Boise area, but it will probably remain in place as you get closer to the Idaho-Oregon border.”
A low-level fog is also forecast for the Treasure Valley Wednesday night, but Wojcik said that you should be able to view the moon through the fog, but it might not be as clear of a view.
After the last full moon of the year, keep an eye out for the other three moon phases within December:
Third quarter: 1:56 a.m. on Dec. 16
New moon: 3:16 a.m. on Dec. 23
First quarter: 6:20 p.m. on Dec. 29
The next full moon visible in Boise will be on Jan. 17.
What does Cold Moon mean?
Moon names have been passed down through generations of Native Americans, who traditionally used the month’s moon as a calendar of the seasons.
December’s full moon is commonly called the Cold Moon, a nod to the month’s chilling temperatures. Here are a few less popular alternative names for December moons:
Drift clearing moon
Frost exploding trees moon
Moon of the popping trees
Hoar frost moon
Winter maker moon
This full moon is also called the long night moon because it’s set to rise during the longest nights of the year. The Winter Solstice occurs on Dec. 21 every year and marks the day with the least daylight and when the sun is set for the most time.
In Boise, the sun will set at 5:11 p.m. on Dec. 21 and not rise until 8:15 a.m. the following morning.
How does Mars make this event special?
This year’s Cold Moon will also coincide with the midpoint of the Mars retrograde, according to the Condé Nast Traveler, which occurs from Oct. 30 to Jan. 13.
Mars retrograde — which occurs about every 26 months — is when Earth’s orbit overtakes Mars’ orbit, making it seem like the red planet is moving up and down due to the tilt of the two orbits.
“Every 26 months, Earth comes up from behind and overtakes Mars. While we’re passing by the red planet this year, it will look to us as though Mars is moving up and down. Then, as we move farther along our curved orbit and see the planet from a different angle, the illusion will disappear and we will once again see Mars move in a straight line”, NASA’s exploration program website states.
This illusion also happens with other planets, NASA states, such as Jupiter.
The moon will completely eclipse Mars approximately an hour after sunset for Idahoans. If you cannot watch in person, Griffith Observatory in Los Angeles, California, is live streaming the event on YouTube.