How many blood moons have there been?

Answer 1

The term "Blood Moon" was coined only recently by John Hagee, a televangelist and pastor of a magachurch in Texas. His book "Four Blood Moons - Something is About to Change" suggests that an unusual sequence of lunar eclipses is a sign of bad times for the future, and especially for Israel.

He draws this imagery from the color of a total lunar eclipse. When the Moon moves into the Earth's shadow and out of the direct sunlight, you might think that the Moon should become dark - but it doesn't. When the Sun sets, we've all seen the red glow in the sky of refracted (or "bent") sunlight going around the curve of the Earth, so that we can see the red light for several minutes after the Sun sets. That red light, having been bent by the Earth's atmosphere, continues out into space and into the Earth's shadow. That red light, from all the sunrises and all the sunsets, all around the world, at once, lights up the Moon with a coppery glow. When there's a lot of volcanic dust and ash in the sky, the sunsets can be fiery red - and the eclipsed Moon will turn very red indeed; a "blood-red Moon". It's just a trick of the optics.

In this case, last night's eclipse (4/14-15/2014) was more rusty orange than fiery red, because the stratosphere is fairly clear of dust.

We see total lunar eclipses - "blood moons" - about once a year, on average, and about every other year (on average) we'll see one from any particular location.

What Hagee is referring to - "Four Blood Moons" - is a somewhat unusual sequence called a "tetrad"; four total lunar eclipses, spaced 6 months apart, in a row, with no partial eclipses between. These "tetrads" go in cycles; none at all for 300 years or so, then 3 centuries of 6-8 tetrads per century. There will be eight tetrads in this century; this is the second.

The Jewish calendar is lunar, so the Jewish holidays are always on the same phase of the Moon each year. This year, the first total eclipse of the tetrad was on Passover, which began last night. (Passover is ALWAYS on the full moon.) The next will happen on Sukkot, the next on Passover, and the 4th on Sukkot next year. It has happened several times before that a tetrad of total lunar eclipses has, coincidentally, happened on the dates of the Jewish holidays. Twice before, in 1949 and 1967, a tetrad on Passover has coincided with significant events in history; Israeli independence, and the victory in the 6-day war, in these cases. So Hagee is claiming that the tetrads were omens of the events.

I personally think this is silly; it's a coincidence.

Answer 2

There have been a total of 89 total lunar eclipses this century, with 27 of those being total lunar eclipses that could be described as "blood moons."