Gullies on Mars: Insights Regarding Contemporary Activity and Plans for Future LargeScale Experiment

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Gullies on Mars Insights Regarding Contemporary
Activity and Plans for Future Large-Scale
Experimental Studies
David A. Crown Planetary Science
Institute Tucson, AZ
PSI Retreat August 20-21, 2007
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• Gullies on Mars
• Discovered in Mars Orbiter Camera images,
• Mars Global Surveyor Mission (1996-2006)
• 10,000s gullies on Martian surface
• Located predominantly in mid-latitude zones
  (30-60)
• Typically found along interior crater walls,
  escarpments, and canyon walls
• Originate 100s m below local topographic high
• Abundant pole-facing orientations
• Geomorphic elements
• alcove
• one or more channels
• depositional apron
• Geologically recent features
• lack of superposed impact craters
• aprons cover recent landforms

Image Width 2.3 km
MOC2-240 NASA/JPL/MSSS
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• Gullies on Mars
• Implications for Martian Water Cycle
• subsurface vs. surface sources of water
• Recent PSI Studies
• e.g., Berman et al., 2005
• Bleamaster and Crown, 2005
• Balme et al., 2006
• Link exposure of gullies and
• degradation of associated ice-
• rich surface mantling deposits
• to solar insolation effects
• Conclusions
• Snowpacks or ice-rich mantles are sources of
  water that carve gullies

MOC2-1292/S10-00964 NASA/JPL/MSSS
Image Widths 3 km
MOC2-317/E16-00043 NASA/JPL/MSSS
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Centauri/Hellas Montes New Gully Deposit
Malin, M.C. et al., Science, 314, 2006

• Formed between 1999 and 2004
• SE wall of 10 km diameter crater
• 38.7S latitude

See also Crown, Berman, and Bleamaster, LPSC
2007
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MOLA 128 pixel/deg DEM/ Viking MDIM 2.1 mpsaic
Hellas Montes
Centauri Montes
Harmakhis Vallis
Geologic Map of the Reull Vallis Region, Mars
S.C. Mest and D.A. Crown 2001 (also Crown et
al., 1992 Price, 1998)
THEMIS IR mosaic
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NE rim
SW rim
derived from MOLA 128 pixel/deg DEM
Centauri/Hellas MontesContemporary Gully
Activity
Image Width 17.4 km
V16997005 NASA/JPL/ASU
Image Width 2.85 km
M04-04175 NASA/JPL/MSSS
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• Insights from Regional Geology
• Crater located in Pitted Plains and adjacent to
  Debris Aprons
• ice-rich surface materials
• Crater Morphology
• NE rim removed
• No distinct ejecta blanket
• Surrounding surfaces have textures typical of
  debris aprons
• collapse and infilling of crater
• Gullies
• Typical gullies incised into mantling deposits
  on N crater wall
• Shallow gullies on S wall (no mantling deposits)
• Gullies redistribute debris apron material on NE
  crater wall
• S crater wall topography consistent with
  digitate morphology

Image Width 1.43 km
M20-00028 NASA/JPL/MSSS
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Melting and Migration of Water in Martian Analog
Hill Slopes Large-Scale Physical Simulations in
Biosphere 2 with Application to Gully Formation
on Mars

• Proposal submitted to NASA Mars Fundamental
  Research Program
• Proposal Team PI Matt Balme (PSI)
• Co-I David Crown (PSI)
• Co-I Travis Huxman (University of
  Arizona/Biosphere 2)
• Scientific Objectives
• To determine whether aquifer breakout or surface
  melting experiments can generate gullies with
  morphologies comparable to martian gullies.
• 2) To identify the parameters that control gully
  formation and channel morphology.
• To estimate volumes of volatiles required for
  gully formation.
• Instrumentation
• Water pumping system Thermocouple array
• Water/sediment collection system Electric heaters
• Scanning LIDAR instrument Video cameras

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Melting and Migration of Water in Martian Analog
Hill Slopes

• Biosphere 2 -
• Large Chamber
• UA Experimental Program
• 30M Endowment!
• Understand how water moves
• through soils, plants, and
• the atmosphere

• Mars Analog Experiments
• test aquifer-breakout and melting models
• 20-30m long, 10m high hillslopes
• use opportunistically before vegetation is
  introduced
• dry experiments dry colluvium
• ice-rich or ice-saturated experiments soak
  hillslope during winter evenings,
• supplement with liquid N sprinkler system
• gtgt Freeze bed to 10 cm depth over 10 x 15 m area

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Melting and Migration of Water in Martian Analog
Hill Slopes

• Small Experimental Chamber
• Constructed within Biosphere 2
• 8m x 4.6m x 2.5m cold room
• Experimental tray and lifting system
• Water reservoirs and pumps
• Insolation system
• Pilot Experiments to test apparatus
• and narrow parameter space

6m x 2m x 1m experimental tray

• Detailed Analog Experiments Initial Series
• 30-35 slope
• Ambient temperature/insolation mid-summer
  daytime at Martian mid, high latitudes
• Ice content dry, ice-rich, and ice-saturated
• Fluid temperature and composition (dissolved
  salts)
• Hillslope materials poorly-sorted colluvium
• fine dust (with high ice content)
• coarse basaltic sand

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David A. Crown Research Interests and Experience

• Planetary Geology
• Mars Geomorphology/Surface Processes, Geologic
  Mapping
• Venus Volcanology, Geologic Mapping
• Io Volcanic Geomorphology, Geologic Mapping
• Physical Volcanology/Remote Sensing
• Lava Flows and Domes
• Lava Flow Fields
• Pyroclastic Deposits
• Field Studies western U.S., Hawaii, Mexico, and
  Central Andes

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2006-2007 Review The Numbers

• 12 Proposals Submitted as PI or Co-I in 2005-2006
• 3 Not Selected
• 1 Still Pending
• 8 Selected for Funding!
• New Proposals Submitted in 2006-2007 4
• Funded NASA Projects 13 (11 with PI at PSI)
• Planetary Geology and Geophysics Program
• Mars Data Analysis Program
• Outer Planets Research Program
• Education/Public Outreach Program
• Journal Articles and Geologic Maps
• 6 published, 1 in press, and 4 in review