Actually it'd be more like a small Neptune/Uranus than a large Earth. Those two planets are made up mostly of a water/ammonia/methane mixture with a solid core

Actually it'd be more like a small Neptune/Uranus than a large Earth. Those two planets are made up mostly of a water/ammonia/methane mixture with a solid core and a H/He outer atmosphere. http://en.wikipedia.org/wiki/Neptune#Composition_and_structure http://en.wikipedia.org/wiki/Neptune#Composition_and_structu...