It is currently Tue Oct 24, 2017 5:54 am

Author Message
Post  Post subject: Size of rocky planets  |  Posted: Sun Jan 10, 2016 7:03 pm
User avatar

Joined: Tue Feb 19, 2013 5:02 pm
Posts: 281

How large could a rocky planet be? It seems that at some point the planet would hold onto too much gas to be a rocky planet. Even figuring lower average density than the Earth I would think there is a point of no return from being a mini Neptune at least...

Post  Post subject: Re: Size of rocky planets  |  Posted: Sun Jan 10, 2016 10:15 pm
User avatar

Joined: Thu Aug 04, 2011 8:35 pm
Posts: 4883
Location: Cardiff, Wales

not totally sure, but it's not only size that matters, but also how close it is to its sun + how strong the sun shines
after all, the T Tauri wind early in a star's life blows a lot of the inner planets atmosphere away + afterwards its solar strength defines whether water will appear as ice, liquid or vapour, or a combination of all three

"Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
"Someone is WRONG on the internet" (xkcd)

Post  Post subject: Re: Size of rocky planets  |  Posted: Sun Jan 10, 2016 10:49 pm

Joined: Wed Sep 02, 2015 7:34 pm
Posts: 217

Good question. I was able to find some info:

http://www.universetoday.com/13757/how- ... anets-get/
What’s the largest possible rocky planet? For this I put in an email to Dr. Sean Raymond, a post doctoral researcher at the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado. Here’s what he had to say: “The largest “terrestrial” planet is generally considered the one before you get too thick of an atmosphere, which happens at about 5-10 Earth masses (something like 2 Earth radii). Those planets are more Earth-like than Neptune-like.”

The term Super-Earth also is used by astronomers to define planets bigger than Earth-like planets (from 0.8 Earth-radii till 1.25), but smaller than mini-Neptunes (from 2 Earth-radii till 4).[7] This definition was made by the Kepler Mission.

Display posts from previous:  Sort by  
Print view

Who is online
Users browsing this forum: No registered users and 0 guests
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
Jump to:   

Delete all board cookies | The team | All times are UTC

This free forum is proudly hosted by ProphpBB | phpBB software | Report Abuse | Privacy