<P> Current conditions in the Martian atmosphere at less than 1 kPa (0.15 psi) of atmospheric pressure, are significantly below the Armstrong limit of 6 kPa (0.87 psi) where very low pressure causes exposed bodily liquids such as saliva, tears, and the liquids wetting the alveoli within the lungs to boil away . Without a pressure suit, no amount of breathable oxygen delivered by any means will sustain life for more than a few minutes . In the NASA technical report Rapid (Explosive) Decompression Emergencies in Pressure - Suited Subjects, after exposure to pressure below the Armstrong limit, a survivor reported that his..."last conscious memory was of the water on his tongue beginning to boil ." In these conditions humans die within minutes unless a pressure suit provides life support . </P> <P> If Mars atmospheric pressure could rise above 19 kPa (2.8 psi) then a pressure suit would not be required . Visitors would only need to wear a mask that supplied 100% oxygen under positive pressure . A further increase to 24 kPa (3.5 psi) of atmospheric pressure would allow a simple mask supplying pure oxygen . This might look similar to mountain climbers who venture into pressures below 37 kPa (5.4 psi), also called the death zone where an insufficient amount of bottled oxygen has often resulted in hypoxia with fatalities . </P> <P> Mars lacks a magnetosphere, which poses challenges for mitigating solar radiation and retaining atmosphere . It is thought that the localized fields detected on Mars are remnants of a magnetosphere that collapsed early in its history . </P> <P> The lack of a magnetosphere is thought to be one reason for Mars's thin atmosphere . Solar wind--induced ejection of Martian atmospheric atoms has been detected by Mars - orbiting probes, indicating solar wind has stripped the Martian atmosphere . While Venus has a dense atmosphere, it has only traces of water vapor (20 ppm) because it has no magnetic field . Earth's ozone layer provides additional protection . Ultraviolet light is blocked before it can dissociate water into hydrogen and oxygen . </P>

How do you create an atmosphere on mars