On Saturday, for the first time since 1993, the Moon is going to be full at almost the exact same time it's closest to earth. So if you've got livestock you need to sacrifice, now's the time to do it!

The Moon will be less than one hour away from perigree (the fancy science word for "point on the Moon's elliptical orbit at which it's closest to earth") on Saturday—the same day that a Full Moon is scheduled (on God's calendar). This means it'll be 14 percent larger than usual! Or, at least, it'll appear 14 percent larger than normal, since the Moon does not, according to scientists, change size. This happens once every "18 years or so," so the next time you get a perigree Full Moon, Justin Bieber will be in his mid-30s.

According to NASA, your best bet is to find the Moon when it's close to the horizon, and look at it through a foreground object, like a tree, triggering an optical illusion called, imaginatively, the "Moon illusion" that will make it appear huge, and compel you to mate, or whatever.

[NASA]