Mars Atmosphere

Martian Atmosphere

  • Carbon dioxide 95%

  • Molecular Nitrogen 2.85%

  • Trace levels of water vapor, oxygen, carbon monoxide, hydrogen and noble gases

  • Density 20g/m3 (about2% of earths value)

  • Temperature - Below Zero to -60 °C

  • Surface Pressure - 610 pascals(0.088psi) which is 0.6% of Earth’s value

  • Prevents liquid water on the surface

  • Studies say it used to be thick


Density

  • High density in spring + fall decreases 25% in the winter when CO₂ partly freezes at pole caps

  • Highest atmospheric density on mars is equal to the density 35 km above the ground on Earth (0.020kg/m³)

  • Has been losing its mass to space since it’s core slowed and the atmosphere still leaks gases.

  • Cooler than Earth, because of distance from Sun.

  • Effective temp. is 210K

  • Surface emission temp. is just 215K; analogous to inland Antarctica

  • Although it consists of primarily CO₂ the greenhouse effect is weak due to lower density of CO₂.


Dust Devils/Storms

  • Dust devils and storms are prevalent; sometimes observable by telescopes

  • One time in 2018 one was even visible with the naked eye

  • Global dust-storms occur every 5.5 Earth years; threaten operation of rovers.

  • Dust storms suggested to be related to the 2 moons gravity.


Oxidization

  • Oxidized atmosphere

  • Photochemical reactions oxidize it by oxidizing organic species and turning them in CO₂ or CO.

  • Most sensitive methane probe (ExoMars Trace Gas Orbiter) found no methane, unexpected levels of methane have been found, may be a biosignature. However, interpretation of measurements is still highly controversial and lacks a scientific consensus.