Sunday, December 23, 2012
A Fabulous New Saturn Image
This magnificent (but artificial color) image of the ringed planet Saturn was assembled and enhanced from 60 different pictures taken with the Cassini spacecraft. You are looking up at Saturn from a perspective below its rings, at a time when the Sun happened to be directly behind Saturn. Thus we are seeing the planets and the rings back-lit, something we can never see from Earth.
The image is constructed not merely with visible light pictures, but also with some in the infra-red (commonly called heat rays). So this is not what your eyes would see if you (like Cassini) were orbiting Saturn -- this is a view only our sophisticated instruments can make available. And the details have been enhanced to show you the complex structure of Saturn's rings (made up of billions of chunks of mostly water ice, all moving around the equator of Saturn in a traffic pattern so vast it puts the Los Angeles freeway system to shame.)
From one side to the other, Saturn's giant ring system spans 170,000 miles across. This means that if you were to take the ring system off Saturn and put it next to the Earth, it would almost fill the space between the Earth and the Moon.
Near the top of the picture, you see the round dark shadow that Saturn casts on its own rings. Below that shadow, the greenish glow is light reflected from the rings on to the cloudtops of Saturn.
The pictures that make up this fantastic mosaic were taken from a distance of about 500,000 miles from Saturn (quite close in astronomical terms.) Just look at all the structure you can see in the ring system, which consists of many, many ringlets.
What a beautiful holiday ornament this planet makes! Happy Holidays.