Quote:
Originally Posted by CraigS
Carl;
Oh well looks like it won't be long before we find it all out …
It'll be good to get more data.
I must admit, I secretly harbour doubts about the whole moon origin theory (yep an opinion .. no evidence).
I've been looking at some of the latest Cassini data/picckys and one has to wonder just what forces and process steps actually occur, in the aggregation (clumping) of orbitally floating material, ultimately resulting in something big .. like a moon …
… And then how the heavy stuff like iron ends up in the middle in a molten/liquid state.
I understand the classic explanation .. but data about Saturn's rings should be showing us the real thing. I'm not so sure its obediently following this theory, though  
Cheers |
Once the material aggregates, a combination of factors heats the body up so that the heavier material sinks to the core of the planet and the lighter material floats to the surface. Most of the heating comes from the impacts of objects into the growing planet/moon and from internal heating caused by gravitational contraction and radioactive decay.
An object the size of the Moon can form very quickly...within a decade or so. A planet like the Earth can take a lot longer....upto 20-30 million years, simply because it's so more massive than a satellite like the Moon.
The reason why Saturn's rings haven't aggregated into a Moon is because of orbital resonances between the particles and the gravitational influence of the planet itself. Although they're not all that old, probably only a few tens of million years old. They'll eventually dissipate and/or aggregate into a moon or two. Whether they survive could be problematical.