How can you not love Cassini? The latest treat NASA’s spacecraft has provided us is the first ever movie of Saturn’s incredible aruroras.
The high-resolution video was assembled from 472 still images, spaced over 81 hours in October, that show the phenomenon in three dimensions. The lights can be seen as a rippling, vertical sheet up to 750 miles high above Saturn’s northern hemisphere.
“The auroras have put on a dazzling show, shape-shifting rapidly and exposing curtains that we suspected were there, but hadn’t seen on Saturn before,” Cal Tech scientist Andrew Ingersoll, a member of the Cassini imaging team that processed the new video, said in a press release. “Seeing these things on another planet helps us understand them a little better when we see them on Earth.”
NASA’s Cassini spacecraft has returned many truly amazing images of Titan, Saturn and Enceladus, but the aurora video is one of the more spectacular views yet seen of another planet.
Each image has a 2 to 3 minute exposure time, and together they reveal that Saturn’s auroras are rapidly changing, as on Earth. But because of Saturn’s lighter, primarily hydrogen atmosphere, the lights reach much higher than in Earth’s heavier oxygen and nitrogen atmosphere.
http://www.wired.com/wiredscience/2009/11/video-saturns-spectacular-aurora-in-action/