EAS206 Lecture Notes - Lecture 12: Valles Marineris, Noachian, Tharsis Montes
• Distance from Sun is 1.5x compared to Earth
• Mars can tilt over itself quite significantly and has implications for its poles
MOLA
o MOLA – laser altimetry = showing topography of Mars
▪ Southern highlands
• Older surface
▪ Northern lowlands
• Younger
o Hellas Planitia, Argyre Planitia, Chryse, Amazonis
▪ Large impact basin
▪ Low plain areas
o Terra = like highlands on Venus
o Olympus Mons
▪ Largest volcano in the Solar system
o Tharsis Montes, Elysium Mons
▪ Mountains are volcanoes
o Valles Manneris
▪ 4000 km valley
• Thought that water has flowed out of the surface
• Hemispheric Dichotomy
o Differences between the 2 halves of Mars
▪ Heavily cratered southern highlands vs northern lowlands
o Fundamental problem in Mars geology
o Mechanism unknown
▪ Leading hypothesis = GIANT IMPACT!
• Polar caps = water and carbon dioxide ice
• Dominant Geological Processes
o Volcanic Activity
o Crustal fracturing (Valles Marineris)
▪ ~Tectonic activity
o Hydrology (water/ice cycle)
▪ Through channels, polar caps
o Wind deposition/erosion
• Mars does have a core
o Significant amount of sulfur compared to the Earth
o Weak magnetic field
▪ No active dynamo
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o More data expected on the internal structure of Mars in near future with NSA
InSight Mission
o Crust has variable thickness
o Atmosphere
▪ Originally from degassing but the atmosphere has become thinner over
time
• Probably due to the gases from the upper atmosphere
o Do’t hae speifi saples fro the ertai hroologial ties of the Mars like
on the Moon
• Geologic History of Mars
o Earliest Noachian
▪ Magma ocean – study of meteorites
o Noachian Epoch
▪ Dendritic valleys
• Something happening with the water
• Oldest area
• Cratering on Mars
o Central: 15 – 100 km
o Hellas
▪ Filled i so do’t see the
multirings
o Rampart craters are unique to
Mars
▪ Muddy flow
• Early lava flows
o Analogous to Moon mare?
• Dendritic valleys
o Denser atmosphere = LIQUID WATER STABLE**
▪ ** (LIQUID WATER NOT STABLE TODAY ON MARS)
o Cove characteristic
▪ Water coming out beneath the surface and flowing out
(different from rainfall)
• Earth = dissected terrain
o Do’t hae that o Mars
o Water is seeping out from the ground
o Early Hesperian
▪ Patera
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