Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: fanofpi on 05/05/2010 14:30:04

Title: Is there a maximum size for terrestrial planets?
Post by: fanofpi on 05/05/2010 14:30:04

Jane Huckins  asked the Naked Scientists:
   
Listening to the Naked Astronomy (http://www.thenakedscientists.com/HTML/podcasts/astronomy/) podcast, another listener's question about rings around terrestrial planets made me think of the following question.

I'm curious to know if there is a maximum size a terrestrial planet can be.

Certainly in our solar system, the giant planets are all gas.

Is this a reflection of some physics principle of which I am woefully ignorant?

What do you think?

Title: Is there a maximum size for terrestrial planets?
Post by: syhprum on 05/05/2010 19:44:16

The concensus of opinion seems to be that after a rocky planet accumulates more than 14 Earth masses the escape velocity becomes sufficiently high for it to rapidly accumulate Hydrogen and helium and transform into as gas giant.