Isaac
09-07-04, 11:32
By Richard Black
BBC science correspondent
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The UV images show interior rings of red "dirt"
The Cassini-Huygens mission which reached Saturn last week has sent back images and data which may reveal the origin of the planet's famous rings.
Pictures showed bumps and curves in some of the rings, while instruments have been able to analyse what the rings are made of.
Cassini has also provided close-up pictures on two of Saturn's moons.
Cassini's path took it between two of Saturn's rings, and the pictures it has produced are simply stunning.
The rings ripple and shimmy - in one image, the thin outer F-ring snakes across the Saturn sky like a newly cracked whip.
Cassini's instruments, meanwhile, are showing scientists why the rings have these features.
"We knew there was a pair of moons, one on each side, that were somehow interacting with the ring," says Professor Carl Murray from Queen Mary University of London.
"So I was sitting looking at the images, and I noticed that there appeared to be like a stream of material coming from the F-ring to the inner of the two moons, Prometheus," he says.
"That was confirmation of a theory that had been produced over four years ago; that's very satisfying."
Ice and dirt
Saturn's rings were discovered by Galileo. Space scientists refer to them by letter, listing the major regions (from the inside) D, C, B, A, F, G, E. Cassini-Huygens passed between F and G when it arrived at the planet just over a week ago.
Images taken in the ultraviolet during that orbit insertion and released this week depict the rings in shades of turquoise and red.
The red indicates sparser ringlets believed to be made of particles that are "dirty" and possibly smaller than those in the denser, icier ringlets, which are shown in turquoise.
The dirt is likely to contain silicates and organic material, scientists say. The ice is likely to be a mixture of water and other substances such as ammonia.
http://img22.exs.cx/img22/2438/3384.jpg
Outer rings, shown in turquoise, contain more ice
Some of this dirt seems to be the same material which dominates the surface of the outer moon, Phoebe, adding weight to the theory that the rings formed from the demolition of a previous moon.
The biggest moon of all, Titan, is believed to be the only body in the Solar System other than Earth with liquid on the surface.
Cassini has already been able to peer through its dense clouds, photographing a large crater, deposits of ice, and lines and circles of unknown origin.
The images of Titan and Phoebe are strangely reminiscent of photos of the Earth and our own Moon, taken decades ago by the earliest space missions.
They are so clear that you struggle to remember that they are coming from a distance of one-and-a-half-billion km.
BBC science correspondent
http://img22.exs.cx/img22/6715/3383.jpg
The UV images show interior rings of red "dirt"
The Cassini-Huygens mission which reached Saturn last week has sent back images and data which may reveal the origin of the planet's famous rings.
Pictures showed bumps and curves in some of the rings, while instruments have been able to analyse what the rings are made of.
Cassini has also provided close-up pictures on two of Saturn's moons.
Cassini's path took it between two of Saturn's rings, and the pictures it has produced are simply stunning.
The rings ripple and shimmy - in one image, the thin outer F-ring snakes across the Saturn sky like a newly cracked whip.
Cassini's instruments, meanwhile, are showing scientists why the rings have these features.
"We knew there was a pair of moons, one on each side, that were somehow interacting with the ring," says Professor Carl Murray from Queen Mary University of London.
"So I was sitting looking at the images, and I noticed that there appeared to be like a stream of material coming from the F-ring to the inner of the two moons, Prometheus," he says.
"That was confirmation of a theory that had been produced over four years ago; that's very satisfying."
Ice and dirt
Saturn's rings were discovered by Galileo. Space scientists refer to them by letter, listing the major regions (from the inside) D, C, B, A, F, G, E. Cassini-Huygens passed between F and G when it arrived at the planet just over a week ago.
Images taken in the ultraviolet during that orbit insertion and released this week depict the rings in shades of turquoise and red.
The red indicates sparser ringlets believed to be made of particles that are "dirty" and possibly smaller than those in the denser, icier ringlets, which are shown in turquoise.
The dirt is likely to contain silicates and organic material, scientists say. The ice is likely to be a mixture of water and other substances such as ammonia.
http://img22.exs.cx/img22/2438/3384.jpg
Outer rings, shown in turquoise, contain more ice
Some of this dirt seems to be the same material which dominates the surface of the outer moon, Phoebe, adding weight to the theory that the rings formed from the demolition of a previous moon.
The biggest moon of all, Titan, is believed to be the only body in the Solar System other than Earth with liquid on the surface.
Cassini has already been able to peer through its dense clouds, photographing a large crater, deposits of ice, and lines and circles of unknown origin.
The images of Titan and Phoebe are strangely reminiscent of photos of the Earth and our own Moon, taken decades ago by the earliest space missions.
They are so clear that you struggle to remember that they are coming from a distance of one-and-a-half-billion km.