Thursday, April 27, 2006

stunning

The photo here was taken on March 16 by the imaging camera onboard the Cassini spacecraft, presently in orbit around Saturn. Even though the spacecraft is 1.3 million miles from the planet, giant Saturn still fills the view. Before I point out particulars, this image has to first be appreciated for the staggering beauty it captures. The coloring shown here is approximately what the human eye would see. The almost imperceptible changes in color across Saturn reveal the complicated chemistry at work in the clouds. The famous rings of Saturn are seen edge-on, cutting through the middle portion of the image. Intricate shadows of the rings are cast across the northern hemisphere. Notice that the sunlit portion of Saturn is at an angle to our view in the image. Like the Earth, Saturn has a rotational tilt that produces seasons. In this image we can see that Saturn's northern hemisphere is tilted away from the Sun. The tilt allows the rings to shadow the northern hemisphere and may produce the noticeable "bluing" of the clouds in the northern hemisphere. Think of it as a cold "wintering" effect. The hairline detail of the ring shadows easily shows us how complicated yet finely tuned the rings are. Countless particles ranging in size from that of smoke to a small car have a particular place in this ring system. Finally, the very intriguing moon Enceladus can be seen skirting the ring plane on the right of the image. Cassini has found that Enceladus has an abundance of water that is actively involved in surface processes there. This makes Enceladus an important target in our understanding of the role water plays in the origin of life. Click on the image, and enjoy.