The Washington PostDemocracy Dies in Darkness

For the first time in 13 years, a full moon rises this Friday the 13th

While especially spooky, this full moon is unusually diminutive — a micromoon

September 13, 2019 at 10:35 a.m. EDT
A full moon rises beyond downtown Kansas City on Aug. 14. (Charlie Riedel/AP)

(This article has been updated.)

Coming this Friday night: the spookiest full moon in 13 years.

This Friday the 13th full moon is the first since January 2006. Only about one percent of full moons fall on a Friday the 13th.

But this full moon, most commonly known as the harvest moon, will appear much smaller than most. That’s because the moon will be at apogee, or the farthest point in its roughly four-week orbit. Timeanddate.com estimates a “micromoon” appears 14 percent smaller and 30 percent dimmer than the widely reported “supermoons” that dominate the news.

Though there is no universal definition governing what qualifies as a supermoon or micromoon, Time and Date says micromoons must be more than 251,655 miles away from Earth. Friday night’s moon will be 816 miles farther than that.

Supermoons, on the other hand, must be at least 2,039 miles closer to Earth than a micromoon. Most of the time, the moon sits somewhere in between those bounds.

For a micromoon and Friday the 13th full moon to occur together is extraordinarily rare. The last time it happened was in 1832 and it won’t happen again for more than 500 years according to Tony Rice, a meteorologist and engineer at NASA.

The moon rises over Washington at 7:31 p.m. Friday although clouds may be obscure the view. But, if there are breaks in the clouds, just look to the east about five minutes after sunset, and you’ll see the orange disk poking above the horizon. Until it’s firmly planted high in the sky, however, it’ll be tough to appreciate just how small it looks.

If you’re looking for a fun Friday night activity, considering inviting your friends and/or resident canine to howl with you at the lunar disk. While clouds could spoil the view in Washington, clear skies are likely in New England and much of the western half of the county (outside the Pacific Northwest). Moonrise also occurs between 7 and 7:30 p.m. in Boston, Denver, and Los Angeles (local time).

Some call the harvest moon the “corn moon,” since September marks a time during which farmers in the Plains typically begin harvesting their corn. Farther north, some may wait a bit later.

This Friday the 13th full moon won’t technically reach peak illumination until 12:32 a.m. Eastern time on Saturday, but for all practical purposes is considered full Friday night (it will be a Friday night full moon in central, mountain, and western time zones). This was also the case in January 2006, when the moon rose the night of the 13th but became full on 4:48 a.m. on Saturday, the 14th.

The next time we’ll have a moon approaching fullness on Friday the 13th (before achieving total illumination the next morning) will be in a little over 13 years, in May 2033.

And if you’re looking for something really riveting, mark your calendar for 2037. There will be two blue moons in a span of three months — a blue moon defined as the second full moon in a calendar month. They’ll occur on Jan. 31 and March 31, both months that will also feature a full moon on the first of the month. In addition, March 13, 2037, falls on a Friday.

What a time to be alive.