Karim Jaafar/AFP/Getty ImagesThe moon appears red during a lunar eclipse in the Qatari capital of Doha, 28 August 2007.
It's going to happen again tonight, and be visible across North America.
"The moon will continue to progress into the shadow, and then at approximately 2:41, it will be completely in the shadow, 2:41 Eastern Time, 11:41 p.m. Pacific Time. And for 72 minutes, while the moon is completely immersed in the shadow of the Earth, one would think that since the shadow is going to cut off all sunlight from the moon, that it would black out completely. It will not."Instead, around the time of total eclipse, it's going to appear to light up like a coppery orange or reddish ball, and the reason for that is that the sunlight is going to be strained through the Earth's atmosphere, and our atmosphere is going to act like a lens and bend that ruddy hue — the same ruddy color that you see in sunrise and sunset — onto the surface of the moon while it's immersed in the shadow."