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.

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