Saturn's colours revealed
2004-07-23 08:06
Pasadena - The international Cassini spacecraft sent back a natural-colour image of Saturn showing the planet's rings are shades of pink, grey and a bit of brown, scientists announced on Thursday.
The image was taken on June 21, a few days before the spacecraft entered orbit, from 6.4 million kilometres below the rings.
The rings are mostly ice, which is white if it is pure. Researchers at Nasa's Jet Propulsion Laboratory believe the different colours reflect the presence of other materials, such as rock or carbon compounds.
Detailed close-ups sent immediately after Cassini entered orbit on June 30 were in black and white. Another vivid set of ring images released previously used infrared photography.
The seven major rings are named A through G, although they are not arrayed in alphabetical order.
The brightest part of the new image is the B ring, a nearly 25 745-kilometre-wide ring that has many bands with a distinct sandy colour.
Colour variations in the rings were previously seen by the Hubble Space Telescope and the Voyager spacecraft that flew past Saturn in 1980 and 1981. But the variations are more distinct as seen from Cassini, Nasa said.
Cassini is the first spacecraft to orbit Saturn. The $3.3bn mission is a joint project of Nasa and the European and Italian space agencies.
- AP