Blood Moon is sometimes used to describe 4 total lunar eclipses that occur in a row. The term may have also come from the reddish glow a full Moon can take on when the Earth casts its shadow on it and eclipses it.
Total lunar eclipses do not occur often – only about 1 in 3 lunar eclipses are total, and about 4 to 5 total eclipses can be seen from any single location on Earth in a decade.
Every once in a while, however, 4 total lunar eclipses happen in a row. This rare occurrence is called a lunar tetrad. The eclipses in a tetrad occur 6 months apart with at least 6 full Moons between them.
The 2014–2015 lunar tetrad gathered a lot of attention because of claims by some religious organizations that the eclipses in the tetrad were a sign of the end times. Some even called the eclipses Blood Moons after a statement in the Book of Joel, that referred to the Sun turning dark, and the Moon turning red before the second coming of Jesus.
Christian pastors Mark Blitz and John Hagee are thought to have been instrumental in popularizing the idea of the prophetic nature of the 2014–2015 Blood Moons, which had special significance because they coincided with important Jewish festivals. The April 15, 2014 and April 4, 2015 Total Lunar Eclipses occurred at the same time as Passover, while the October 8, 2014 and September 28, 2015 eclipses occurred during the Feast of Tabernacle.
The 2014–2015 Lunar Tetrad or Blood Moons were significant for one additional reason – allfour total lunar eclipses were visible from most of the United States. The September 28, 2015 eclipse was the last total lunar eclipse visible from mainland USA until January 31, 2018.
Four Blood Moons “Tetrade”
Three times in last 500 years:
-1493-94 Fall of Spain, Jews expelled. Columbus discovers America (“Infant Nation”)
-1949-50 Follows Israel declare a Nation
-1967-68 Six Day War