Lecture 12 Ch 8 170172,179181 Ch 9 196209

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Lecture 12 Ch 8 170-172,179-181 Ch 9 196-209

• Earth's Moon
• Mars
• Geology
• Weather/Climate
• Water
• Future research

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Mars
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Mars - Geology

• No or very, very small B field - probably
  stronger one in past
• Surface contains many Fe oxides (red color)
  volcanic rock
• Volcanoes
• Olympic Mons
• 3x higher than Everest
• 340 miles across
• Slope few degress!?!
• Very few craters present, suggests young age
  (hundred(s) of millions of yrs)

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Mars Pathfinder (1997)
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Mars Pathfinder (1997)
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Olympus Mons
MOC 79ft resolution
MOC lava flow
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Mars - Weather/Climate

• General properties
• Temp depends on location/season - usually well
  below 0 C
• Pressure lt 1 Earth's atmospheric pressure
• Very little atmosphere at present
• 95 carbon dioxide, 3 N
• Water, carbon dioxide sublimates (solid to gas)
• Seasons
• Orbital inclination (tilt)
• AND DISTANCE TO SUN (?!?!?)
• Eccentricity 0.093 (Earth's 'e' is 0.017)

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Mars - Climate/Weather

• Clouds
• Dust
• Water-Ice (generally around mts)
• Carbon Dioxide (dry ice haze)

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Mars - Dust Storms
HST
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(Running with the) Martian Dust Devils!
MGS 1999
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Martian Water-Ice Storm
HST WFPC2 low pressure stormw/ water-ice clouds
- 1100 x 900 miles
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Effects of Seasons/Cloud Variability

• Seasonal trends in N/S Martian polar caps
• Water carbon dioxide caps
• emma.la.asu.edu/webdata/dust_mov/dust_mov_lg.html
• btc.montana.edu/ceres/Images/mars_polarcap.mpg

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Effects of dust storms on caps -from Bonev et al
2002
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Water on Mars

• Water-ice seen in polar regions
• 2001 Mars Odyssey (What are you doing, Dave?)
• Gamma ray spectrometer - indirect detection of
  substantial subsurface water at S pole
• In upper meter of soil
• Enough water to fill L. Michigan a few times
• Evidence of past surface flows

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Water flows on Mars in past?

• Evidence from
• Runoff channels
• Similar to runoff which occurs on Earth after
  rainstorm
• Implies ancient Mars had a much different climate
  - w/ a thick atmosphere surface water
• Outflow channels
• A little younger
• MUCH larger volume of water shot out from
  reservoir
• Pathfinder(97) landed in one of these drain
  basins
• Gullies on crater walls (MGS 2000)
• RECENT WATER FLOW!!!!

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Runoff Channel
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Outflow Channel
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Gullies in Craters
VikingI - 1978
MGS - MOC - 2000
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What Causes Gullies in Craters?

• 1) Seeping ground water?
• 2) Mudflows from collapsing permafrost layers?
• 3) Pressurized outflows(bursts)?
• 4) Water flow underneath snow layers (Feb 14,
  2003 - not in your textbook!!!)
• See nasa press release 2/15/03 on course website

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Future ...

• Check out mars.jpl.nasa.gov/missions/future/2005-p
  lus.html
• Mars Express (2003/03) atmospheric/surface
  studies from polar orbit
• Mars Exploration Rovers (2003/04) Similar to
  Pathfinder - 2 rovers
• Mars Reconnaissance Orbiter (2005) High res
  surface study - includes MARCI - UT PBJ
• A little more distant ... (note timelines for
  these usually untrustworthy)
• Smart Landers/Long-Range Rover (2009?) prelude to
  sample return
• Scout Missions (2007ish?) AIRPLANE/BALLOON
  platforms on Mars!!!!!
• mars.jpl.nasa.gov/technology/airplanes/index.html
• mars.jpl.nasa.gov/technology/balloons/index.html
• Sample Returns (2014ish) surface and subsurface
  sample returns to Earth
• May involve surface drilling?