I'm playing in a game with some new planets...
ASTEROID, NEUTRON, METAL, CRYSTAL
I'm trying to figure out the stats of these planets, and wanted to know if they come from some kit, ie with easily quanitifiable stats, or they come from the SYSOP's planet editor, and therefore my only way to figure out the planets is through trial and error.  Info would be appreciated.

Other than stock planets, all planets you encounter were created at one time by an owner of a TWGS.
I have no idea what edit you are playing, or who created it, so I would suggest to you, pop some planets, look at them, if they don't appear good, blow them, and pop another until you either find good ones, or have looked through them all.