Scientists find a planet so light it could float on water.

[Bear]

Isn't there a theory that states that all planets start as gas giants?

The theory states that during the final stages of development, some stars let off a massive amount of energy, "blowing" the gas off of nearby planets. Thus, planets close to the sun don't have tons of gas, and all thats left are the cores, a.k.a small planets like ours. Therefore, the stars that didn't go through this process can have massive gas giants very close to them.

Anyone else heard of this? I read it a while ago...

[Preturbed]

That ones new to me.

I agree with the guy who said its a brown dwarf. It sounds like a double star system that burned out its first half.

[Sithdarth]

Originally Posted by Bear

Isn't there a theory that states that all planets start as gas giants?

The theory states that during the final stages of development, some stars let off a massive amount of energy, "blowing" the gas off of nearby planets. Thus, planets close to the sun don't have tons of gas, and all thats left are the cores, a.k.a small planets like ours. Therefore, the stars that didn't go through this process can have massive gas giants very close to them.

Anyone else heard of this? I read it a while ago...

The thing is even during the first few millions of years during star formation the gas and dust near the star is hotter and just generally oribiting a lot faster. This tends to make it clump into denser bits. Also, all the heavy elements sink toward the center of the cloud leaving mostly hydrogen and helium out on the edges. Then when every star finally takes that last step into fusion it blasts all the excess gas out the the entire planetary system. Its just that the outer most planets had both more stuff to eat to begin with and slightly more time to eat. Not to mention the blast does miss some of the stuff in the outer parts of a planetary system leaving some left overs to eat. At least that's the current theory.

Originally Posted by Preturbed

That ones new to me.

I agree with the guy who said its a brown dwarf. It sounds like a double star system that burned out its first half.

Most large gas giants like Jupiter or larger are in fact brown dwarfs. That really doesn't make them not a planet. Not to mention stars do not burn out into brown dwarfs. They burn out into white dwarfs, neutron stars, or black holes. A brown dwarf is simply a large ball of gas that just missed accumulating enough mass to intiate sustained fusion.

Not to mention the article mentions that there is already a second star in the system right in the first sentance of the second paragraph.