There are 11 different types of planets in the game, but only 9 of those are able to support a Biodome on it.

The 2 uninhabitable planet types are Gas Giants, & Tiny Planets. Gas Giants are about double the size of regular planets, & Tiny Planets are about a quarter the size of regular planets.

The other 9 habitable planet types are:

Each Habitable Planet Type has a Unique Building that can be Constructed only on that Planet Type.