Tetrads ("Blood Moons")

When the Moon passes into the shadow of the Earth, the moon goes dark.  It actually turns a red color since some of the light is bent through earth's atmosphere, so it's like a sunset on the Moon.

However, there is some mild hysteria about the lunar eclipse coming up, and I want to clarify a few things.

For those out of the loop, this is the last of four lunar eclipses that have fallen 6 months apart, each of which have fallen on major Jewish holidays.  Some are saying it is the end of the world.  Many are calling the eclipse a "blood moon," a term I hadn't heard prior to 2014.  I would prefer to avoid that term, since it seems like it is just designed to make people afraid.

So lets start with some facts:

• Lunar eclipses happen about twice a year 6 months apart. 
• Lunar eclipses always happen on a full moon.  
• The Jewish calendar is based on the moon.
• Passover and the Feast of Tabernacles are on full moons six months apart. 

So the concurrence of all these things isn't as uncommon as it originally seemed.  If the first of four total eclipses land on a Passover, they should all land on these Jewish holidays.  It is, however, a lot less common to get four total lunar eclipses in a row (called a "tetrad"), since eclipses are often partial, not total.  This is the 55th tetrad in the last 2,000 years.

Although tetrads are less common, the most common months for them to start are in March and April, the months that Passover can fall in.  13 of the 55 have had the first eclipse fall on 14th or 15th of Nissan.  Of those, 4 were over a leap year, so the eclipse isn't on Passover the following year.  One other is strange and the moon is a little off the calendar, and the eclipse falls on the 13th of Tishri, prior to the Feast of Tabernacles.  Not quite sure what happened there.

Anyway, not counting those five, that means this is the 8th that has happened in the last 2,000 years.  (The others being in 162, 795, 842, 860, 1493, 1949, and 1967)  The world didn't end any of those times.  I don't expect it to this time, either.  The next time a tetrad falls on those four holidays will be in 2582.

Another important consideration, is that the Bible isn't as specific as people are (perhaps) assuming it is.  Joel 2:31 says, "The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord come."  (This is again repeated in the New Testament, and in the Doctrine and Covenants)  It doesn't say anything about tetrads, nor about Jewish holidays.   It doesn't even have to be an eclipse—I'm sure there are other phenomenon that can make the moon look red.

I don't want to give the wrong impression, though.  I'm not saying "don't worry; eat, drink, and be merry!"  I am saying something more like, "You shouldn't sell your home and spend all your money."  We should always live spiritually as though Christ may return at any time.  But we should live physically as though we plan to die of old age.