The most important factor of a planet's atmosphere is simply having one. Specifically, having air pressure similar to Earth's 100,000 pascals (Pa) at sea level. From orbit, your planet's atmospheric pressure will affect the visibility of the air above the surface: too thin and it will be invisible, too thick and it will be opaque.
Terraforming[edit | edit source]
A minimum amount of Pressure is necessary to build a supply of Oxygen.
Changing Pressure also affects accumulation of Temperature. "Atmospheric Thinning" causes loss of heat, while "Atmospheric Thickening" causes increase of heat. High Pressure also creates the status of Temperature that is "Retained by Atmosphere".
The state of Water is affected by Pressure. At less than 600 Pressure, all water held as vapor or ice even though the temperature is lower than the normal boiling point. When 600 Pressure is breached (and given the temperature is within range), it all turn into water at once, which can completely destroy every outpost and city you have built immediately.
Habitability for plants and microbes to grow on a planets surface requires an atmospheric pressure of 10,000 to 190,000 Pa. Habitability for animals and humans outside of a Hab building is a narrower range between the 50,000 and 150,000 Pa.
If your world's pressure is over 200.000 Pa, it will be so thick that you can no longer see your world's surface.
Buildings[edit | edit source]
|Biofixture Lab||-Pressure, +Biomass (Biomass only) +Oxygen (Biosphere only)|
|Hydrogen Processor||-Pressure, +Temperature, +Water|
|AtmoGen Suite||+Pressure, +Oxygen|
|Pocket Mine||+Pressure, +Oxygen, +Credits|
|Carbon Fixer||-Oxygen, +Pressure|
|Kelp Farm||+Oxygen, -Pressure|
|Ice Launcher||-Water, -Pressure|
|Aquifer Network||+Water, +Pressure|
|Spaceport||+Population, +Pressure, +Credits|