View Full Version : Cassini from new scientists magazine

13-07-2004, 12:07 AM
Some of the most spectacular images ever of Saturn's enigmatic rings have been returned by the Cassini space probe.

The pictures were captured using Cassini's Ultraviolet Imaging Spectrograph (UVIS) instrument and have been colour-enhanced to illustrate the different materials that lurk within the planet's famous discs. They were taken on 30 June shortly before the spacecraft slipped into orbit around the planet by drifting between two of its rings.

Astronomers at the University of Colorado in Boulder, who analysed the images, say they confirm that Saturn's rings get dustier and icier towards the edge. The dust and rocky debris found in Saturn's rings is thought to be made of silicates and organic materials, while the ice is likely to be a mixture of water and other substances such as ammonia
One of the images shows the planet's middle ring, known as the A ring, in impressive detail. The dust-strewn interior of the ring is coloured red but the less dusty, more dense ice-filled regions towards the edge are shown in turquoise. The thin red band towards the edge of Saturn's A ring is a 325-kilometre void known as the Encke gap.
Another picture shows the point at which two of Saturn's inner rings, the C ring and the B ring merge. This also reveals a general pattern from dusty "red" inner bands to "blue" ice-rich outer bands within the rings.

Scientist believe Saturn's rings formed a few hundred million years ago when debris from colliding comets and moons was drawn into orbit around the planet by its gravitational influence.

Debris varies in size from tiny dust particles to boulders 10 metres across. The rings extend more than 190,000 kilometres but are just 1.5 kilometres thick.

Studying Saturn's rings could help scientists understand of the formation of Solar System itself, as the rings are thought to provide a miniature model of the dust and ice bands that circled the Sun before the planets coalesced