Blood Moon 2015 is just one more in a series of astronomical events that have caught the fascination of some religious folks.

A “blood moon” — not a scientific term — is a lunar eclipse phenomenon that only occasionally occurs. There is no blood, of course. Light refraction through the Earth’s atmosphere gives the upcoming lunar eclipse a reddish hue.

In terms of significance, it holds no real value in and of itself. It’s simply a chance alignment of shadows and orbits that is only observable from where we happen to be in this solar system — and only certain places on our globe. If you were on any other planet, it would be a non-event.

But that doesn’t stop evangelical author and doomsday-sayer John Hagee from making Armageddon hay over Blood Moon 2015.

In his best-selling book Four Blood Moons: Something Is About to Change, Hagee quotes from the Old Testament book of Joel as the basis for his prognostications:

“The sun will be turned into darkness And the moon into blood Before the great and awesome day of the LORD comes.” Joel 2:31

Hagee says that it is rare for these “blood moons” to land on so many Jewish holidays in a row. He states several times that “NASA” is forecasting these events, to lend his argument some air of scientific authority.

“None of these dates are mine, half of them belong to God and the other half to NASA. And they are both to reasonable intelligent sources of reference.”

But full moons and lunar eclipses — including lunar eclipse 2015 — are not NASA-grade predictions. Any decent almanac will list them. What he does not mention is that the Jewish calendar is a lunar calendar. Most Jewish holidays are based around full moons.

And, because of the overlap distance between the Jewish calendar and a standard western calendar, there is a lot of room for fudging on dates.

But Hagee asks that faith-pinging and wallet-swelling question about Blood Moon 2015: “Is this the end of the age?”

“They will be a world shaking event… The heavens are God’s billboard, and when something big is about to happen He gives planet earth a signal that something significant is about to happen. Pay attention! NASA said these four blood moons are coming. God has said through Joel and St. Peter, Listen!”

Even some more mainstream church organizations are dismissing Hagee’s argument as book-selling hype.

“The coming four blood moons will be the eighth time this has happened since 1 AD. They mean nothing as far as the Bible is concerned… When these four blood moons come and go, Hagee will change his view and keep right on preaching to his faithful undiscerning crowd.”

Look to the skies for Blood Moon 2015. You’ll get to see a cool-looking red moon. If you also see someone Raptured up, that’s a bonus. But mostly you’ll see John Hagee counting his money.