Last Full Moon of the Decade Will Fall on 12/12 at 12:12 A.M. for Americans in Eastern Time Zone

The final full moon of the decade is set to grace the skies this week.

Full moons are an astronomical phenomenon that occur roughly once a month when the Earth is positioned between the sun and the moon. When this happens, the face of the moon that we can see is fully illuminated by our star, appearing like a perfect circle.

Technically the term "full moon" refers to the specific moment when the Earth's only natural satellite is directly opposite the sun. This moment will take place at 12:12 a.m. EST or 9:12 a.m. PT on Thursday, December 12.

However, the best time to view the full moon will be just as it rises above the eastern horizon on December 11—around 4:20 p.m. EST. (The exact time of moonrise will vary slightly depending on where you are in the country. Check the timings here.)

According to The Old Farmer's Almanac, the full moon in December has traditionally been referred to as the "Full Cold Moon" by some Native American groups, not surprisingly, because temperatures in the Northern Hemisphere tend to be low at this time of year.

It is also known as the "Long Nights Moon" because it occurs close to the winter solstice in the Northern Hemisphere. Technically, this is the precise moment that the Earth's North Pole is tilted furthest away from the Sun. In 2019, the solstice will take place on Saturday, December 21 at 11:19 p.m. EST.

The December solstice marks the shortest day of the year in the Northern Hemisphere—i.e. the one with the fewest daylight hours and the longest night—when the Sun will be at its lowest position in the sky.

The December full moon has also traditionally been known as the "Moon Before Yule"— a name derived from the ancient pagan festival of Yuletide, which was historically observed by Germanic peoples in late December.

The next full moon—the first of the next decade—will fall on January 10, 2020. This moon is often called the "Wolf Moon" although it is also known as the "Old Moon," "Ice Moon" and by other names.

The December 2019 full moon will occur shortly before the peak nights of the Geminid meteor shower on December 13 and 14. In fact, the moon will be around 96 percent full on these nights, meaning that the light reflecting off it will likely obscure some of the dimmer meteors.

However, up to 20 meteors an hour may still be visible so it's worth going outside to try and spot some.