Another full moon makes an appearance this weekend. This one, dubbed the Buck Moon by Algonquin tribes from the northeastern United States, was so named for the time when adolescent deer sprout velvety new antlers in the summer.
NASA’s Gordon Johnston writes that the Buck Moon goes by several different names. Indigenous tribes sometimes call it the “thunder” moon because of early summer’s frequent storms. Back in the day, Europeans sometimes called this moon the “hay” moon after summer haymaking activities, or the “mead” moon.
[Related: What is a full moon, anyway?]
This year the Buck Moon will likely shine with a reddish-orange glow, but not for typical reasons. There are normal astronomical causes for vividly-colored moons: The rusty hue of blood moons are caused by total lunar eclipses, for example. But the Buck Moon’s unusual color will arise from earthly events—namely, the smoke and haze drifting across North America from the wildfires out West.
According to the US National Interagency Fire Center, 79 fires are currently burning through at least 13 states, extending as far north as British Columbia, Canada, as well.
The red skies in the aftermath of a fire are due to smoke particles interfering with how sunlight travels through the air. Light comes in a spectrum of wavelengths. Fire smoke blocks out the shorter wavelengths of blues, greens, and yellows, while allowing the longer waves of red and orange through. Since the glow of the moon is just reflected sunlight, smoke interferes with moonlight as well.
Fires aside, this summer will be full of great skygazing opportunities, according to Johnston. Saturn will be close to Earth and shining brightly on August 2, while Jupiter will do the same on August 19. The Southern Delta-Aquariids meteor shower, most clearly seen from the Southern Hemisphere, is also currently visible. It will peak on July 30, but folks will be able to see it until about August 23. The Perseid meteor shower has already started as well, and can be witnessed hanging around the constellation Perseus until August 24.
The full Buck Moon, however, will only appear for about three days, from Thursday night to Sunday morning, by Western Hemisphere times, and will peak on Friday night. If you’re looking to get a glimpse of the full Buck Moon this weekend, be sure to check for your local moonrise and moonset times to ensure the best views.