The Mungo Says Bah blog has some nice ones.

In case you’ve forgotten (or never really knew, as in my case), a lunar eclipse takes place when the earth gets right in the way of the sun, (i.e. right exactly between the sun and the moon) such that the earth’s shadow (lighter shadow is the penumbra, and the much darker umbral shadow appears later) appears across the face of the moon. The blood-red or orange colour is the result of the final bits of sunlight that are able to refract around the earth’s atmosphere – the earth’s atmosphere blocks the blue light and allows through predominantly the red portion of the spectrum which we see.

I hope one of my parallel-universe selves is an astronomer. I keep thinking I’d love to stare at stars and planetoids all night but never seem to get around to it.