A Thin Atmosphere is a atmosphere with a standard oxygen/nitrogen mix, which is breathable without assistance.
Surface Pressure & Water Properties
Surface Pressure & Water Properties Surface
0.43 atm 77.5°C 0.55 atm 84°C 0.7 atm 90°C
History & Background (Dossier)
At altitudes above 2,500 meters on Terra, the air pressure drops to around 0.70 that of sea level. This is equivalent to the IISS Scout Code atmosphere type of Thin. Sophonts who are not adapted to such conditions can suffer from altitude sickness, with headaches, nausea, extreme tiredness, breathlessness and body pain. Associated high blood pressure can cause complications for pregnant women.