Ever mention something that happens “once in a blue moon”? Well brace yourselves—that moon will be here at the end of the month.
Tonight, August 1, is the month’s first full moon. But then we get a bonus as well, on the very last day: August 31 will showcase a second full moon, and this one will be blue, according to Space.com. The last two-full-moon August occurred in 2008.
Although the moon’s hue can be changed by environmental events, “blue moon” is the term given to the second full moon in a calendar month, according to Space.com—at least in contemporary parlance. A 1946 misinterpretation of the term in Sky & Telescope magazine led to that interpretation of the term, however. The original explanation is rather complicated and is detailed in the Farmers’ Almanac.
When it does change color, it is generally because of soot and ash particles in the atmosphere, such as those from forest fires, as famously happened above eastern North America in 1950 after massive forest fires in western Canada. Mount Pinatubo’s eruption in the Philippines in June 1991 created blue moons worldwide, Space.com notes. The term has also been coined to refer to uncommon events, a practice that Space.com reports first occurred in 1824, though the Farmers’ Almanac dates that use back to 1821.
Blue or not, the full moon of August 31 will be a heavenly sight to behold, as will its counterpart tonight, August 1.
More August full moon names: The one tonight is known as the Full Sturgeon Moon, according to Space.com, so-named for the fish whose most plentiful haul is this month, in the Great Lakes, Lake Champlain and other large bodies of water. Some tribes call it the Full Red Moon, according to the 2012 Old Farmer’s Almanac, or the Green Corn Moon or Grain Moon.
The August 31 full moon will be known as the Full Corn Moon, or the Fruit Moon, Space.com said.