Witness the cold micromoon — the last full moon of 2021 to shine in the night sky

 

The last full moon of 2020, also known as the cold moon, rises behind the San Gabriel Mountains at sunset, as seen from the Kenneth Hahn State Recreation Area on December 29, 2020, in Los Angeles.

According to NASA, the last full moon of 2021 will achieve maximum illumination on Saturday, December 18, but you can follow its passage across the sky beginning shortly before sunset.

The Mohawk people call this full moon the "cold moon" since it falls just a few days before the longest night of the year in the Northern Hemisphere, often known as the winter solstice. It's no surprise that it's also known as "the long night moon."

Noah Petro, chief of NASA's planetary geology, geophysics, and geochemistry lab, said, "My encouragement is always that people come out whenever they can to gaze at the moon." "The moon is at its largest for a split second, yet we can't see it with our naked eyes."

Unlike a solar eclipse, watching the full moon does not need precision, he noted.

Petro recommended that moon watchers go out on Friday night to stake out a place and look up and east for the finest view. "You want to avoid large buildings, bright lights, and other obstacles."

Because the full moon in December falls on such a long night in the Northern Hemisphere, it will "glow above the horizon for a longer amount of time than most full moons," according to CNN meteorologist Tom Sater.

Why this is a micromoon

The full moon on Saturday will also be 17 percent smaller than the typical full moon, according to Petro. Because the moon travels around the Earth in an elliptical orbit, it gets closer and farther away at different periods. The full moon on Saturday happens to fall on the apogee, or point where the moon is farthest from the Earth, making this moon a micromoon.

A supermoon, on the other hand, happens when the moon is at perigee, or its closest approach to the Earth. The months of April, May, and June experienced supermoons this year.

The moon will appear full to human eyes a day or two before or after peak illumination, according to Petro. "If you can't get out Saturday, get out Sunday."

The last full moon of the decade, with a saffron-colored tinge, hovers over LA on December 11, 2019.

Moon lovers in the Southern Hemisphere can go outside late at night to see a full moon. However, it will be the opposite of what people in the Northern Hemisphere see, according to Petro. "The moon isn't rotating; it's your sense of where it is because you're on this planet."

According to Star Walk, other names for this December full moon include "bitter moon" in China and "oak moon" in mediaeval English. Because it will be the first of four full moons in the summer season in the Southern Hemisphere, Saturday's full moon will arrive close the December 21 summer solstice, prompting some to dub it the "strawberry moon," as it was in the Northern Hemisphere.