Here are the relevant stats for the respective homeworlds as well as a mineral report on the known surveyed bodies in the system, Earth is a special case and will be described in the next post.
Venus: Colony Cost: 0.00, Temperature: 27.1, Gravity: 0.91, Orbit: 108m Nitrogen 53%, Oxygen (0.2) 26.7%, Safe Greenhouse Gas 20.0%, Pressure: 0.75
Mars: Colony Cost: 0.00, Temperature: 25.8, Gravity: 0.38, Orbit: 229m Safe Greenhouse Gas 45%, Nitrogen 36%, Oxygen (0.1) 18.1%, Carbon Dioxide 0.54%, Pressure: 0.55
Ganymede: Colony Cost: 0.00, Temperature: -6.8, Gravity: 0.15, Orbit: 1.07m Safe Greenhouse Gas 77%, Nitrogen 15.4%, Oxygen (0.1) 7.7%, Pressure: 1.30
Venus and Mars make excellent vacation spots, Ganymede is cold as balls and has a thick atmosphere. Also of note is the low Oxygen content compared to Earth of all the homeworlds, this is due not to laziness on the part of the game creator, but because initial terraforming was done only until things were good enough, plans to make everything a lot more perfect went by the wayside once the wars started.
Mineral Report:
Venus
Duranium 65,700 Acc: 0.9
Neutronium 28,470 Acc: 0.2
Corbomite 26,910 Acc: 0.2
Tritanium 57,930 Acc: 1
Boronide 14,550 Acc: 0.2
Mercassium 22,410 Acc: 0.3
Vendarite 29,460 Acc: 0.2
Sorium 370,875 Acc: 0.9
Uridium 49,710 Acc: 0.3
Corundium 18,060 Acc: 0.2
Gallicite 13,680 Acc: 0.5
Mars
Duranium 101,100 Acc: 1
Neutronium 71,300 Acc: 0.2
Corbomite 53,200 Acc: 0.2
Tritanium 109,000 Acc: 0.2
Boronide 69,400 Acc: 0.4
Mercassium 186,700 Acc: 0.9
Vendarite 94,400 Acc: 0.2
Sorium 290,000 Acc: 1
Uridium 82,400 Acc: 0.2
Corundium 106,400 Acc: 0.9
Gallicite 52,000 Acc: 0.4
Jupiter
Sorium 1,615,000 Acc: 0.6
Europa
Vendarite 3,939 Acc: 0.3
Ganymede
Duranium 154,620 Acc: 0.9
Neutronium 57,690 Acc: 0.3
Corbomite 29,190 Acc: 0.2
Tritanium 27,930 Acc: 0.2
Boronide 36,300 Acc: 0.6
Mercassium 22,890 Acc: 0.9
Vendarite 24,270 Acc: 0.8
Sorium 430,425 Acc: 0.7
Uridium 10,440 Acc: 0.2
Corundium 26,370 Acc: 0.7
Gallicite 36,800 Acc: 0.4
Titan
Duranium 11,233,040 Acc: 0.7
Uridium 679,503 Acc: 0.1
Neptune
Sorium 10,349,680 Acc: 0
These are based on pre-war survey records which are incomplete at best, the new factions only have survey knowledge of the 8 planets, Pluto, and the potentially terraformable moons.