December’s full moon will soon reach peak illumination. Here’s what to know

By Taylor Nicioli, CNN

(CNN) — As the winter nights grow longer, those in the Northern Hemisphere will want to keep an eye out this weekend for the last full moon of the year. The silvery orb will shine bright in the sky for a hair more than 16 hours on Saturday evening into Sunday morning.

Known as the long night moon or the cold moon, it’s set to reach peak illumination at 4:02 a.m. ET Sunday, according to The Old Farmer’s Almanac. However, the moon will appear round to the naked eye for about three days, according to NASA.

For those in the Southern Hemisphere, which had a long visibility moon in June, the December full moon will appear for a shorter time and will follow a lower arch in the sky, said Sara Russell, research scientist and head of the Planetary Materials Group at London’s Natural History Museum.

“For those of us in the northern hemisphere, the Moon will seem to reach higher in the sky than you might expect,” Russell said in an email.

The sun, moon and Earth are on about the same plane, with the full moon occurring when Earth is between the moon and the sun as the moon orbits our planet. “In December, when it is winter in the northern hemisphere, the Sun is low and has a short track across the sky, so the opposite Moon has a high and long track,” Russell added.

Observing the cold moon

The cold moon’s name is a nod to the bitter weather typically found in the Northern Hemisphere this time of year. The name comes from the Mohawk people, according to The Old Farmer’s Almanac, which has names for each full moon that historically derive from Native Americans, Colonial Americans or other sources.

For best viewing of the cold moon, Russell recommended looking when it has just risen or is about to set to see it near the horizon. Wrap up in warm layers if you’re in colder weather and aim to look when there are clear skies in your area, she said.

“We are so lucky on Earth to have the Moon. There’s nowhere else in our Solar system where there is a planet and moon so proportionately close in size — the Moon is almost like our smaller twin,” Russell said. “It is better at preserving all of its history than is the surface of the Earth, and we can look up to its cratered surface to see how battered by impacts both the Moon and Earth have been over their 4.5 billion-year history.”

Those observing the moon can ponder the questions yet to be answered about the neighboring celestial object, such as the mysteries surrounding the far side of the moon, theories about the water-rich lunar poles or the possibility of humans one day living on permanent bases there, Russell said.

Upcoming celestial events

This year, the December full moon occurs one week before the winter solstice, an astronomical event caused by the Earth’s tilt, that marks the Northern Hemisphere’s longest night and shortest day and vice versa for the Southern Hemisphere.

This year’s winter solstice, when Earth’s axis is tilted the farthest away from the sun, will be at 4:21 a.m. ET December 21, according to EarthSky.

The next full moon will be the wolf moon on January 25, according to the Farmers’ Almanac.

Meanwhile, there are two meteor showers to close out the year; the Geminids will be seen blazing in the night sky until the shower’s finality on December 21, while the Ursids will peak December 21-22, according to the American Meteor Society.

The-CNN-Wire
™ & © 2024 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.