I know, it's been a long time coming.
But here's a first draft of what I talked about a month or two ago: adjusting the text showing up in the Astronomy Screen when selecting the objects.
TEXT "inf-plcls-A"
0 "Planet suitable for human life, with a dense atmosphere consisting of a breathable mix. The active biosphere may pose hitherto unknown dangers." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-A"
0 "Moon suitable for human life, with a breathable atmospheric mix and active biosphere. The lower gravity may cause health issues in the long run." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-B"
0 "Planet with a dense non-breathable atmosphere and rampant surface conditions. By utilizing an extensive terraformation process, it may be made suitable for living." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-B"
0 "Moon with a dense non-breathable atmosphere. May be suitable for small-scale colonization under domed or subterranean facilities to mine minerals and metals." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-C"
0 "Planet without an atmosphere. The tests discovered massive amounts of frozen water beneath its surface. May be suitable for vacuum colonies if proper minerals en metals are present." $$data "08/12/2004 10:22:16" "" 1
END
TEXT "inf-mncls-C"
0 "Moon without an atmosphere, rich in minerals and metals. Suitable for scientific -and mining outposts only." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-D"
0 "Huge gas giant, with frequent, high speed storms often visible as large ovals on the upper cloud layer of the planet." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-D"
0 "Huge gas giant, with frequent, high speed storms." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-E"
0 "Giant asteroid, with too little mass to establish a spheroidal shape. Most likely the result of a collision between planetesimals." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-E"
0 "Asteroidal satellite, probably the remnant of a collision between two asteroids. Low on raw materials, unsuitable for mining." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-F"
0 "Comet with a long tail of gases and dust." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-G"
0 "Planet with a tenuous atmosphere. Liquid water may exist on the surface when atmospheric pressure becomes high enough, and the planet orbits within a suitable distance from its sun." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-G"
0 "Moon with a tenuous atmosphere. Liquid water may exist on the surface when atmospheric pressure becomes high enough, and the moon orbits within a suitable distance from its sun." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-H"
0 "Terrestrial planet experiencing a run-away greenhouse effect in the atmosphere due to proximity to its sun. By interfering with its biosphere, it can be made suitable for open-air habitation." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-H"
0 "Large moon experiencing a run-away greenhouse effect in the atmosphere due to proximity to its sun. By interfering with its biosphere, it can be made suitable for open-air habitation." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-I"
0 "Dwarf planet, the remnant of a protoplanet unable to attract enough material for reaching planetary size. Has enough mass to become a spheroid under its own gravity." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-I"
0 "A dwarf planet's satellite, mosttimes just an irregular shaped chunk of rock and/or ice. In rare cases it has enough mass to show a spheroidal form." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-plcls-J"
0 "Terrestrial planet with a dense atmosphere containing some toxic trace elements. By interfering with its biosphere, it can be made suitable for human habitation." $$data "07/23/2004 15:07:36" "" 1
END
TEXT "inf-mncls-J"
0 "Large moon with some toxic trace elements in the atmospheric mix. By interfering with its biosphere, it can be made suitable for human habitation despite the lower gravity." $$data "07/23/2004 15:07:36" "" 1
END
There's a few more classes that can be added. Ice giants (unofficial label for smaller gas giants like Uranus and Neptune) and waterworlds (a planetclass between gas giants and terrestrial planets with a deep ocean, surface completely covered by water) come to mind.
But perhaps ice giants are superfluous? Any other type of world that's so obvious that I forgot about it?