Friday, December 07, 2007

Flying Saucers

Our Cassini spacecraft continues to make big discoveries. New data shows that moons Atlas and Pan are surrounded by huge "spare tires," giving them the shape of flying saucers. The CG image is based upon Cassini photos. Since the plane of these bulges coincides with the Ring plane, scientists have concluded that the moons are made of Ring materiel piling up along their equators. Their rotation could not stretch them into this shape, because each moon takes a 14-hour day to revolve. The strange shape offers clues to how these worlds or our Earth formed.

Atlas and Pan both orbit within Roche's Limit, a mathematical boundary within which moons are not supposed to form. Inside this limit, tidal forces from Saturn were thought to tear liquid objects apart. The ice crystals that make up the moons form loose "rubble piles" that behave as a liquid. Being made of ice crystals with many empty spaces in between, the moons have a density much less than liquid water. The spare tires show that they are continuing to attract particles. It is odd that objects with less density than liquid exist inside Roche's Limit, within which liquid objects are not supposed to form at all.

If Pan and other moons formed around singularities, these tiny holes would explain both their formation and shape. Pan's 10^{15} kg mass could easily contain a 10^{12} kg singularity without getting sucked up. Even if you were only 3 meters from such a tiny Black Hole, you would feel no more gravitational pull than you do in Manhattan. Pan orbits within the Encke Gap of A Ring. Outer and inner boundaries of the gap correspond to Lagrangian points in the Pan-Saturn system. Inside the gap particles will be drawn toward Pan, eventually colliding to build the spare tire.

Since Saturn's Rings contain conditions similiar to our Solar System's formation, this offers clues as to how other worlds formed. The moon Iapetus displays a strange ridge around its equator, which may have a similiar origin. Scientists have suggested sending probes to tunnel through Europa's kilometres of ice. A similiar probe could someday burrow into Atlas and possibly find a Black Hole.

H.G Wells' Invisible Man was finally discovered by tracks he left in snow. Saturn's Rings are literally a field of ice in which the tracks of invisible objects can be seen. If our Solar System contains tiny Black Holes, this is a good place to look. Singularities would explain how these small moons formed and stay together. Black Holes may be the missing link to how Earth and other worlds were created.

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Anonymous Anonymous said...

So that lazy old Atlas is taking a break and sitting down!

9:20 AM  
Blogger nige said...

The Atlas and Pan "flying saucer" shaped moons around Saturn actually look like the flying island of Laputa, in the satirical attack on science by Swift hundreds of years ago (it was supposed to be held up by a giant loadstone which repelled the Earth's magnetic field). See:

I can't find the image of Laputa from the book (which really looks identical to Atlas and Pan), but some variants are illustrated here, here, here, here, and here.

3:50 AM  
Anonymous dmduncan said...

You were teasing me with that title, weren't you?

2:30 PM  

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