New Year's Day Super Moon: What Is the Wolf Moon and When Is It Happening?

December's full super moon, as seen from France. Loic Venance/AFP/Getty Images

Updated | Moon enthusiasts have a lot to look forward to in 2018, and that will start with the very first day of the year. That's because thanks to a fluke alignment between the lunar cycle and our calendar cycle, we'll be starting off the new year with a brand new full moon. January's first full moon, which is nicknamed the Wolf Moon, will peak on January 1, at 9:24 p.m. ET, although it will appear full and bright for the days immediately surrounding the new year as well.

Although there are still cultures that peg their calendars to the lunar cycle as well as Earth's seasons, the Gregorian calendar that is most commonly used today does not. That means that it's a complete coincidence that this year's very first full moon will fall on the first night of the year.

In 2009, a full moon fell on December 31, but the last time a full moon peaked on January 1 was in 1999.

In another celestial fluke, the moon is currently in the section of its orbit when it happens to lie a little closer to Earth, what astronomers call near perigee. That means that the New Year's moon will appear just a tiny bit larger than the average moon. The precise degree varies with where in the sky the moon is and when in the moon's orbit you're comparing it to, but the effect is always less than about 14 percent.

January's full moon is also often referred to as the Wolf Moon, under the system of full moon names originally used by New England's native Algonquin tribes. Other nicknames for the first full moon of the year include Holiday Moon among the Chinese; in the southern hemisphere, where January marks early summer instead of early winter, it is often known as the Hay Moon, the Buck Moon or the Thunder Moon.

Read more: Super Blue Blood Moon 2018: What It Is and When to See It

The fact that the full moon is arriving so early in January also opens up the month to a second full moon, called a blue moon. The phenomenon is unusual, but perhaps not as unusual as the saying would suggest: Because the lunar cycle plays out over the course of about 29.5 days, it's completely feasible to fit a second full moon in a month with 31 days, like January. That blue moon, which will also mark a lunar eclipse, will arrive on January 31.

This story was updated to include historical information about previous New Year's full moons.