Once In A Red Moon

I've always hated that expression denoting rarity: "Only once in a blue moon." Red moons, which happen during lunar eclipses, are pretty rare too, and can actually happen. So, why is the moon red during a lunar eclipse instead of black or some other color? Because the sky is blue. Follow the link for a time lapse slideshow of today's lunar eclipse, and for the explanation of our atmosphere scattering blue light, but not scattering red light as much, so that the moon receives a little bit of red light as it passes through and hits the moon in our shadow. It's an extreme sunset!