Several people sent me a link to a short and pretty little video showing two cycles in the sky: the Earth's rotation, and that of Jupiter. Nicely done! I was surprised to see the video was made by Thunderf00t, whom I didn't know was an astronomer. Thunderf00t is well-known on YouTube for his great "Why People Laugh at Creationists" series, showing in very basic terms why creationists are laughably wrong. Well, it would be laughable if they weren't trying to brainwash entire generations of schoolkids, but that's another story. I hope in between fighting for science he makes more astronomy videos like this one. It's very cool.