Saturn and Jupiter may have started off as tiny pebbles

Updated
Saturn and Jupiter May Have Started Off As Tiny Pebbles
Saturn and Jupiter May Have Started Off As Tiny Pebbles


Saturn and Jupiter may be gas giants now, but according to some experts, they were once nothing more than tiny pebbles, and a recent study supports that assertion.

The prevailing theory is that such planets were formed when larger bodies collided and combined.

However, this is a problematic explanation for a number of reasons.

It's assumed it would have taken longer for the planets to form than it appears they did.
The recent findings of planetary scientist Harold Levison and his colleagues support the suggestion that the genesis of gas giants was the collection and melding of centimeter to meter-wide rocks.

Not only would it be a much quicker formation process than the combination of larger bodies, the calculated results are in sync with known entities in the outer solar system.

Their analyses also addressed an important factor in the formation process, which is the competition between nascent planets for survival and domination.

Noted Levison, "If pebbles form slowly enough to allow the planetesimals to gravitationally interact with one another ... the largest planetesimals have time to scatter their smaller siblings out of the disk of pebbles, thereby stifling their growth."

See gorgeous photos from the Spitzer Space Telescope:

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