Talk:Gem Homeworld/@comment-27487924-20170518022021/@comment-31509668-20170601011435

The Gem Homeworld clearly has an atmosphere or Lars would have died once he left the building. Steven too for that matter as Steven also requires oxygen. From what we've seen of Homeworld so far, we know it has a level of atmospheric oxygen and pressure able to sustain human life comfortably. If we know anything about Lars we know that when he's uncomfortable he will let you know it. If the oxygen level was too high or too low Lars would be feeling painful effects. We also know that atmospheric pressure is at a level comparable to Earth. If it was too low Lars would asphyxiate. If it was too high Lars is at risk of oxygen toxicity.

We also know that surface gravity is close to 1 earth G. Again, Lars would have complained if he felt his body was too heavy or too light. He was able to move and fight comfortably so Homeworld gravity wasn't a hinderance to him.

The big question is how does Homeworld's atmosphere have that much free oxygen. Oxygen will combine with damn near anything. Unless atmospheric oxygen on Homeworld is being replaced all free oxygen molecules would combine into CO2, FeO2, etc. On Earth our abundant plant life keeps pumping fresh oxygen into the atmosphere. Homeworld has no organic life that we've seen so where is the oxygen coming from?

As for needing an atmosphere for life, it is not necessary. There are forms of life on this planet that do not need oxygen. Anerobic bacteria get along just fine without an atmosphere.