[extropy-chat] FWD [forteana] re: Saturn a Comet Nursery?

[Terry W. Colvin]

> Bill asked:
> >>How would they build up to comet size inside Saturn's
> >>Roche limit and then
> >>escape Saturn's gravity intact when they're just
> >>loosely packed balls of ice
> >>and rock?
> 
> Lawrie answered:
> >They could be flexible during formation. They aren't
> >that big, after all. Sort of cosmic slush-puppies.
> 
> Bill added
> Too much flexibility is the problem.
> 
> Another problem I didn't mention earlier is that Saturn's
> rings just don't have a lot of material in them. If the
> current rate of dissipation is normal, they're quite young
> and will be gone relatively soon.

Hi,
Experts (below) may have answers for clumping _and_ resupply of
ring-material (below) but it's a bit iffy att.

If we include the rings of Jupiter, Neptune and Uranus - all big
scoopers-up of debris and incoming stuff - as possible comet sources,
then 

1) ice-clumping (below) _mite_ give needed cohesion.

2) another scenario is chemical bonding of Saturnian clumps (under
radiation effects) partially reproducing "rock-formation" [which on
Earth needs heat and pressure and a _long_ time].

An advantage of that idea is it _could_ give you out-gassing jets to
move them out of orbit, without tides or "Lorenz resonances" (below).

cheers
Ray

< http://www-astro.physics.uiowa.edu/~lam/research/rings/ >
Recent models for the formation of the rings all depend on infrequent,
high speed collisions between satellites and outside interlopers. Dones
(1991) suggests a particularly large event for the formation of Saturn's
rings. Colwell and Esposito (1992a,b) explore the statistics of a
cascade of smaller collisions for the rings of Uranus and Neptune.
The central contribution of this poster is to suggest that tidal
evolution of satellite orbits can serve the function of moving
satellites into the Roche zone from outside.

http://pds-rings.arc.nasa.gov/reference/abstracts/burns1985_01.html
Specific 'Lorentz' resonances, corresponding to particular spatial
periodicities in the magnetic field, occur on either side of synchronous
orbit. Lorentz resonance locations and strengths for the Jovian and
Saturnian rings are described

http://pds-rings.arc.nasa.gov/saturn/saturn.html
The particles in Saturn's rings are composed primarily of water ice and
range from microns to meters in size. The rings show a tremendous amount
of structure on all scales; some of this structure is related to
gravitational perturbations by Saturn's many moons, but much of it
remains unexplained.

RD


-- 
"Only a zit on the wart on the heinie of progress." Copyright 1992, Frank Rice


Terry W. Colvin, Sierra Vista, Arizona (USA) < fortean1 at mindspring.com >
     Alternate: < fortean1 at msn.com >
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