Rotation

Today's Astronomy Picture of the Day is a movie showing Jupiter's rotation.

One of the most memorable observing experiences I had was one cold January night where Jupiter showed particilarly clear. Not only could I see the Great Red Spot, but the major moons and their shadows. As I observed, more and more detail kept "popping" into view on the cloud banks: whorls and festoons. Suddenly I realized that the Great Red Spot had transited across the face of Jupiter and I had very cold feet. I had sat there for several hours that night, utterly captivated by what I had seen.