lesson4d1 working out the global history of mars
TRANSCRIPT
• Mars is massive enough and far enough from the Sun that it should have held on to much of its atmosphere.
• There is evidence that Mars use to have a thicker atmosphere, especially if there was once liquid water on the surface.
• Also, volcanism releases gasses such as CO2, H2O and methane (CH4). This would add to the atmosphere.
• Something else must have happened.
First, did Mars ever have a thicker atmosphere?
Evidence would be if there was ever standing water on Mars.
Spirit and Opportunity think so.
Both landed on Mars in January 2004.Opportunity is still actively researching Mars.
Hematite signal from orbitHematite is an iron compound which typically
forms in the presence of water
Triple combination
• The triple combination of sulfur, chlorine and bromine make the evidence clear that water was present in the rocks.
• These three chemicals are deposited when water evaporates and leaves them behind.
• Combining this with the Hematite which formed within the sedimentary rock layers is conclusive that water was on the surface at Meridiani Planum.
Standing water about 3.7 billion years ago.
• If there was standing water in the distant past on the surface of Mars, then what happened to the atmosphere?
Mars Science LaboratoryLanded on Aug 5, 2012
Determine whether life ever arose on Mars
Characterize the climate
Characterize the geology
Landing site for MSL – Gale Crater
• Landing site