We had a Blue Moon on January 31, 2018. It was a supermoon, too, and underwent a total eclipse (photos here). You’ll see another full moon that carries the name Blue Moon this weekend, on Saturday night, March 31. Both the January and March 2018 Blue Moons are blue in name only. Both are the second of two full moons to fall within a single calendar month. Two Blue Moons in a year is indeed rare. We haven’t had a year with two Blue Moons since 1999 and won’t have one again until January and March, 2037.
In recent years, people have been using the name Blue Moon for two different sorts of moons. The first can be the second of two full moons in a single calendar month, as with the January 31 and March 31 Blue Moons. An older definition says a Blue Moon is the third of four full moons in a single season.
Meanwhile, the month of February 2018 had no full moon at all.
Someday, you might see an actual blue-colored moon. Meanwhile, the moon you’ll see Saturday night won’t look blue, and blue-colored moons in photos – like the ones on this page – are made using special blue camera filters or in a p...