Download Class 9/8/10 - University of Kentucky

Lesson4d1
Working out the global history of
Mars
• 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.
Spirit/Opportunity rovers
Hematite signal from orbit
Hematite is an iron compound which typically
forms in the presence of water
The
Opportunity
landing site
on Meridiani
Planum
Eagle Crater
Inside Eagle Crater
Blue Berries – Hematite spheres
Abrasion tool collects samples
Spectral analysis confirms Hematite
Analysis of rock shows Sulfur, Chlorine and
Bromine: All of which are soluble in water
High sulfur suggests basalt rocks (Jarosite)
that have been dissolved in 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 Laboratory
Landed 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
Smectite clay on earth from 100
million years ago.
Model for the
formation of
Gale crater.