The so-called full "Harvest Moon" will emerge in the night sky this weekend. But don't be spooked by its appearance, it will be much smaller than usual.
The harvest moon is the full moon closest to the autumnal equinox. This year, the moon will turn full just after midnight on Saturday, Sept. 14 for those living in the Eastern Time zone. But for people in the Central, Mountain, or Pacific time zones, this particular Harvest Moon will fall on Friday the 13th.
While a split time-zone full moon is atypical — last occurring in 2014 — a full moon on Friday the 13th nationwide is very rare. The last time the U.S. had a Friday the 13th full moon was on Oct. 13, 2000 and the next one won't happen again until 2049, according to the Old Farmer's Almanac.
What's more, this year's full moon will be smaller than usual because it coincides with apogee — the point in its orbit farthest away from the Earth. This "Micromoon" is the opposite of last year's "Supermoon" when the full moon occurred during perigee, it's closest point to Earth.
For several days after the initial appearance of the harvest moon, the moonrise will come soon after sunset. Traditionally, the additional light early in the evening gives farmers more time to reap their summer-grown crop, hence the name "harvest" moon, according the Farmer's Alamanac.