Late Monday / early Tuesday has the first in a series of four total lunar eclipses — a lunar tetrad — that will take place in 2014 – 2015. Follow this link to learn how to watch this week’s lunar eclipse.

I recently heard someone refer to the coming eclipse as a “Blood Moon eclipse.” I’d never heard that term before, but it has something to do with biblical prophecy. The folks at EarthSky explain:

From what we’ve been able to gather, two Christian pastors, Mark Blitz and John Hagee, use the term Blood Moon to apply to the full moons of the upcoming tetrad – four successive total lunar eclipses, with no partial lunar eclipses in between, each of which is separated from the other by six lunar months (six full moons) – in 2014 and 2015. John Hagee appears to have popularized the term in his 2013 book Four Blood Moons: Something is About to Change.

Mark Blitz and John Hagee speak of a lunar tetrad as representing a fulfillment of Biblical prophecy. After all, the moon is supposed to turn blood red before the end times, isn’t it? As described in Joel 2:31 (Common English Bible):

“The sun will be turned to darkness, and the moon to blood before the great and dreadful day of the LORD comes.”

That description, by the way, describes both a total solar eclipse and total lunar eclipse. Sun turned to darkness = moon directly between the Earth and sun in a total solar eclipse. Moon turned to blood = Earth directly between the sun and moon, Earth’s shadow falling on the moon in a total lunar eclipse.

See the image above for why someone might describe a lunar eclipse as the Moon being turned to blood.

There are eight tetrads in the 21st century, but what’s apparently significant about this tetrad is that it coincides with the Jewish feasts of Passover and Tabernacles. I guess you’ll have to buy the book to see exactly how this fulfills prophecy.