SAN ANTONIO – You’ve heard the saying, “Once in a blue moon.” Well, that’s happening in August.
That saying is used to describe a rare event, but it has an astronomical meaning.
There are two kinds of blue moons, according to NASA, and neither has anything to do with the actual color of the moon.
A seasonal blue moon refers to the third full moon in a season that has four full moons. A monthly blue moon is the second full moon within one calendar month. We see a blue moon about once every three years, on average, according to NASA.
By both definitions, the next blue moon will occur on Aug. 30.
It will also be a supermoon.
A supermoon means that the moon appears slightly larger than normal because it’s at or near perigee — meaning it’s at the point in its orbit that it’s closest to Earth. The moon will appear about 14% bigger in size and 30% brighter compared to the moon at apogee (farthest from Earth). On Aug. 30, the moon will be about 222,043 miles from Earth. There won’t be a closer supermoon until November 2025.
Before the blue moon, we’ll see the “sturgeon moon.”
The first full moon in August — also a supermoon — will be on Aug. 1. It’s named “sturgeon moon” because the fish was once abundant in August in the Great Lakes region. It’s also referred to as the green corn moon, the barley moon and the fruit moon.