Saturday’s full moon (September 10) is also titled the Harvest Moon for those living in the northern hemisphere. The moon officially becomes full when it reaches that point in the sky opposite (180º) from the sun in the sky. This moment will happen on Saturday at 5:59 AM. Eastern Time (0959 GMT). Saturday’s full moon is the one closest to the September equinox, so this year it falls in September, although that title can sometimes be awarded to the October full moon. The 2022 edition of the Harvest Moon comes unusually early, though it could happen as early as September 8 (like 2014) or as late as October 7 (like 1987). Many people think that the Harvest Moon stays in the night sky longer than any other full moon we see during the year, but that is not the case. What sets Saturday’s full moon apart from the others is that farmers at the peak of the current harvest season can work late into the night under the moonlight. It rises around the time the sun sets, but more importantly, at this time of year, instead of rising its normal average of 50 minutes later each day, the moon appears to rise at roughly the same time each night. Below we provide some examples for ten North American cities. Local Moonrise times are provided for September 9th, 10th, and 11th, with the average date being that of the Full Moon Harvest.
(Image credit: Joe Rao) (opens in new tab) In fact, over this three-night span for our relatively small sample, moonrise comes, on average, just over 25 minutes later each night — or exactly half of the normal 50 minutes. A quick study of the table shows that the night-to-night difference is greater for the more southerly locations (Miami, located near 26ºN latitude, sees moonrise come on average just under 36 minutes later). Meanwhile, the difference is smaller in more northern locations (in Edmonton, Alberta, located at 53.6ºN latitude, the average difference is only 12 minutes). The reason for this seasonality is that the moon appears to move along the ecliptic, and at this time of year when it rises, the ecliptic makes its smallest angle to the horizon for those living in the northern hemisphere. Conversely, for those living in the southern hemisphere, the ecliptic at this time of year appears to stand almost vertically (almost at right angles) to the eastern horizon. Therefore, the difference for the time of moonrise exceeds an average of 50 minutes per night. In Melbourne, Australia, for example, the difference from night to night is 72 minutes. Interestingly, for those living near 60º north latitude, the moon does appear to rise at the same time each night around the time of the Harvest Moon. And for those who live even further north, a paradox: the moon seems to rise earlier! In Reykjavik, Iceland (64.2ºN latitude), for example, the moonrise times on September 9, 10, and 11 will be, respectively, 8:51 PM, 8:43 PM. and 8:36 p.m. So from Reykjavík, the moon will appear to rise nearly eight minutes earlier each night. You can check out our guides to the best binoculars and the best telescopes to spot the Harvest Moon. If you’re hoping to get a good photo of the moon, check out our recommendations for the best astrophotography cameras and the best astrophotography lenses. Editor’s Note: If you take a photo of the Harvest Moon and want to share it with Space.com readers, please send your photos, comments, and your name and location to [email protected] Joe Rao serves as an instructor and guest lecturer in New York Hayden Planetarium (opens in a new tab). He writes about astronomy for Journal of Natural History (opens in a new tab), the Rural Almanac (opens in new tab) and other publications. Follow us on Twitter @Spacedotcom (opens in a new tab) and then Facebook (opens in new tab)
