At exactly 8:58 p.m. CST (central time) tonight, the moon will move into Earth’s shadow. The total lunar eclipse, where the moon is completely shaded by the Earth, will start a little more than an hour later at 10:07 p.m. CST, and will last until approximately 11:25 p.m. CST.
You may have heard the term “blood moon” before. Whenever the moon passes into Earth’s shadow, it takes on a reddish color- it can be anywhere from a bright copper to a darker hue, like the color of dried blood. But what causes this?
Well, even when the Earth is between the sun and the moon, some of the light from all of the sunsets and sunrises happening around the rim of the Earth makes it to the moon’s surface. Here’s Alan MacRobert of Sky and Telescope magazine:
“If you were standing on the moon during a total lunar eclipse you would see the Earth as a black disk with a brilliant orange ring around it. And this brilliant ring would be bright enough to dimly light up the lunar landscape.”
It’s this ring of light which gives the moon its blood red color.
Tonight’s eclipse will be the first total lunar eclipse since December of 2011. It will be visible in its entirety across almost the entire continental United States, as well as in parts of Canada and Central America.
You can use the map below to figure out how much of the eclipse will be visible from where you are. Read more from the L.A. Times here.