Published on Mar 25, 2018
Two Blue Moons in one year seem to belie the famous statement: Once in a Blue Moon. And in recent years – with more than one definition for Blue Moons – Blue Moons seem to happen pretty often. Yet it’s indeed quite rare to have two Blue Moons in a single calendar year. It last happened in 1999 and won’t happen again until 2037. March 31, 2018 – presents the second and final Blue Moon of the year. By popular acclaim, a Blue Moon is defined as the second of two full moons to occur in one calendar month. January had two full moons. Now March does, too. http://earthsky.org/tonight/years-2nd... http://earthsky.org/astronomy-essenti... https://www.space.com/35891-march-ful...