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 Post subject: For Astronomers..
PostPosted: Mon Mar 12, 2007 11:57 pm 
98+ BoTM | BoTM | Gold | Rider
98+ BoTM | BoTM | Gold | Rider
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Joined: Thu Mar 23, 2006 12:48 am
Posts: 6624
Location: Kingdom of Ringlé
From a newsletter I subscribe to.. Bloody interesting stuff really.. 8)

"Finally, here are the views that we've waited years for. Sailing high above Saturn and seeing the rings spread out beneath us like a giant, copper medallion is like exploring an alien world we've never seen before. It just doesn't look like the same place."

Friends, as learners, you can probably understand the exuberance of Dr. Carolyn Porco, leader of the Cassini space probe's imaging team. No one had ever seen Saturn's rings from above before. But as scientists gradually pushed their probe into a highly inclined, south-to-north orbit, our cameras could look down on the rings' broad disk.

Cassini has been shooting Saturn close up since July 2004, when the doughty probe began circling the gaseous giant. Since then, it's shown Earthbound watchers both the beauty of Saturn's two-toned blue and gold globe and the violence of its constantly shifting storms, blown about by 1,000-mph (1,600-km/h) winds.

Of course, the really spectacular thing about Saturn remains the rings. All the gaseous giants in our solar system--Jupiter, Saturn, Uranus, and Neptune--have them. But not like Saturn's. So, inquiring minds want to know, how did the broad and beautiful rings of Saturn form?

Astronomical Answer #1

Astronomers figure that our sun formed within a giant cloud of gas and dust. Drawn together by gravity, particles in this cloud coalesced into a rotating pool heated by the energy of the gravitational collapse. In time, this rotating pool was dense enough and hot enough to fire up as a star.

The leftover material around the new star eventually flattened into a similarly rotating disk. Again drawn together by gravity, particles in the disk coalesced into rotating pools. But this time, there simply wasn't enough material to fire up stars. Instead, the pools made planets.

Something similar may have been at work to create the myriad moons around planets like Jupiter, Saturn, Uranus, and Neptune--miniature solar systems all. Maybe, some scientists say, Saturn's rings are just cold bits of primordial soup that never managed to make a moon.

Astronomical Answer #2

Nonsense on stilts, say other scientists. That may be how solar systems form, but it's not how Saturn and its bright rings did. Surely rings 4.6 billion years old would be dirtier, they say, marred by all kinds of dust and debris--like week-old snow. Saturn's rings shine like a new penny.

And surely by now gravitational forces would have cut ancient rings down to size, like the smaller, darker rings of Jupiter, Uranus, and Neptune. Saturn and its rings are the widest planetary body in the solar system.

No, these scientists think that Saturn's rings are a very recent (and perhaps even recurring) phenomenon--such that if dinosaurs had invented telescopes, Galileo Rex might well have spied a ringless Saturn.

Several hundred million years ago, perhaps a cold, moon-sized object from the outer solar system flew too close. Saturn's gravity captured it, and tidal forces ripped it apart. Or maybe a renegade meteor smashed into one of Saturn's own icy moons and broke it apart. Either way, the bright bits of ice in orbit made broad and beautiful rings.

It may add up. The mass of all the icy chunks and bits throughout Saturn's rings amounts to about one medium-sized moon--for despite their reach, the rings are only tens of meters thick. They are, many scientists now think, fragile, dynamic things that only a bit of cosmic luck lets us see.


 Post subject:
PostPosted: Thu Mar 15, 2007 2:27 pm 
BoTM Winner
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Joined: Thu Jan 19, 2006 1:23 pm
Posts: 2734
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Your right that was quite interesting, beutiful images too.

 Post subject:
PostPosted: Thu Mar 15, 2007 9:16 pm 
Dirt Disciple
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Joined: Tue Oct 03, 2006 7:53 pm
Posts: 81
Always love a good space pic - makes you feel so small

 Post subject:
PostPosted: Thu Mar 15, 2007 9:54 pm 
Old School Grand Master
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Joined: Sat May 20, 2006 2:56 pm
Posts: 4776
Location: No brakes? Way to commit soldier.
I've just finished reading 'A Short History of Nearly Everything' by Bill Bryson. It's a great book that talks you through many scientific topics, not least the formation of the universe, planets and life in general.

A couple of chapters deal with our size relative to the size of the universe and the length of our stay here relative to the age of the planet, and that really does make you think about how significant we are!

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