SkyWatch 2012: The Planets

Planets change greatly in appearance over time frames ranging from hours to months. That's both due to superficial effects — rotation revealing different sides of a globe — and fundamental changes on a planet's surface or in its atmosphere.

A number of amateur astrophotographers have stitched their own images together to create movies showing changes on planets, but this is very challenging due to the fact that planets aren't visible continuously from Earth's surface due both to poor weather and Earth's own rotation. To do a really good job of this, you need to start with space-based images.

See, for instance, S&T imaging editor Sean Walker's animation of images from the Hubble Space Telescope to show Saturn's rotation.

But to my mind, by far the most amazing movie of all is the one created by Bjorn Jonsson from photos of Jupiter taken by the Voyager 1 spacecraft. Click below to watch Jupiter's cloud bands rotate, swirl, and evolve over a 24-day period.

Click here to find other videos and images for SkyWatch 2012.