By Nolan Feeney
July 29, 2015

Blue moons aren’t actually blue, but they are as rare as the saying goes.

The second full moon in a month is commonly referred to as a blue moon—we had a full moon on July 2, and we’ll have another this Friday on July 31—but there’s a more complicated definition according to the U.S. Naval Observatory:

Write to Nolan Feeney at nolan.feeney@time.com.

SPONSORED FINANCIAL CONTENT

You May Like

EDIT POST