Composition and Characteristics History Magnetosphere Climate Possible Human Benefits Terraforming
Composition and Characteristics Basics Composition 95.5%CO2 2.7%N2 1.6%Ar 0.13%O, O2 0.07%CO 0.006%H2O OtherO3, H, NO, H2
Color: Peach/Salmon Color. Caused by dust particle pollution
. -Thickness: 6-7 millibars -Structure: Lower<45km. Middle45-110 km. Upper110-200 km
-Air Cycle. The Hadley Cell Cycles. Very similar to Earth air cycles. Based on the Coriolis Effect. Distributes heat from the equator to the poles.
Heat Trapping -Doesn't trap heat very well -Most heat near surface, except for the middle atmosphere. -Dust particles in the middle atmosphere absorb heat from the sun. -Heat in atmosphere is more uniform, does not lose heat proportionally to altitude like on Earth.
-Thickness Less than 1% of the Earths at sea level. Same thickness as Earth's at altitude of 30km. -Earth's atmospheric composition 77%N2 21%O, O2 1%H2O 0.93%Ar 0.035%CO2 OtherO3, H, NO,H2, CO
Can also see Halos on Mars. Halos are Scattered by CO2 molecules in atmosphere.
History First detected by Cassini, in 1672. Saw the Star Phi Aquarii disappear behind Mars 6 minutes from Mars' Disk. Therefore concluded it was very thick. Herschel later in 1783 observed two stars pass through Mars. From results concluded that atmosphere wasn't as thick because the glares didn't change very noticeably. But noted changes in belt's, which were perhaps clouds. "The inhabitants of Mars probably enjoy a situation in many respects similar to ours."-Herschel (35, Sheehan)
How Did it form? Out gassing, similar to Earth's and Venus' Partially through small impacts
What went wrong? Possible large crater impacts ejected atmosphere into space. Perhaps in a period of heavy bombardment that ended about 3.2 Billion years ago. Anything larger than 3 km. Earth and Venus Have more mass, and larger gravitational pulls (higher escape velocities)
Other Theories Ion Sputtering. Erosion by solar particles because of lack of magnetosphere. Large amounts of deuterium 5X that of Earth's But not as much H Sequestration into regolith and/or icecaps Carbon Dioxide stored in poles and in regolith Weathering Carbon dioxide converted into carbonates Possible photochemical reactions Loss of Nitrogen
Magnetic Field Detected by Mars Global Surveyor to be 1/800 that of Earth's at sea level. Used to block harmful solar radiation. Because of weak magnetic field, there is very little Core dynamo in Mars. Therefore also no plate tectonic activity. Evidence suggests that there was a magnetic field of decent strength. Judging that magnetic dust particles distributed by meteor impacts inside of craters forming magnetic alignments
Mars Tilted Axis of 25° Winter in poles convert Carbon Dioxide in atmosphere to solid ice. Almost 1/3 of the atmosphere is converted to ice, to form polar thickness of 1-2 m each year. Water and Carbon Dioxide Sublimation back in the Spring Water in north pole can sublimate in summer to be formed into ice clouds and redistributed around the planet
Circulation Martian Atmospheric circulation similar to Earth’s circulation
Atmospheric Affects on Geography Dust Devils Leave Trails Dust deposits from dust storms Creation/destruction of Sand Dunes
How Can we benefit from the Martian Atmosphere? Extract needed gases, as suggested by Zubrin -Water -Oxygen -Carbon for methane -Could also plant trees to convert Carbon Dioxide to Oxygen.
Protection from falling bodies Although thinner than Earth's, the Martian atmosphere can be made thicker by the greenhouse effect, decreasing the amount of meteors that will reach the surface.
Transportation/Exploration UAV's to explore/map features. May be more effective than satellites UAV's can study the structure of atmosphere
Balloons can take high altitude measurements Possibly transport vehicles
If a thicker atmosphere, can eventually manipulate atmosphere for transportation. Initially, can use flying machines as a type of postal service, or communication.
What Can we learn from Mars? Greenhouse effects Ion sputtering New aircraft design Similarities in planetary history. Finding a link between Earth and Mars.
Possible Terraforming Changes How to terraform the atmosphere. -Suggested use of greenhouse gasses SF6, CnF2n+2, C2F6, SF5CF5, and the chloroflurocarbon family. -Some Fluorine will be needed to make these compounds. -Gases must be able to heat the atmosphere, yet not destroy Ozone. -Suggested that 20 nuclear power plants can raise the temperature of the planet 5°C over a century, but with better gasses, could take only a decade.
Melting the poles, to release Carbon dioxide in the south pole, and water in the north pole.
Possible Consequences? Over pollution Excessive heating Over thicken the atmosphere Could create a 2nd Venus instead of a 2nd Earth