northwestern slope valleys (nsvs): prime candidate site for msl exploration of mars

Northwestern Slope Valleys (NSVS):

Prime Candidate Site For MSL Exploration

Of Mars

J.M. Dohm, R.C. Anderson, V Baker, T.M. Hare , S.J. Wheelock

Outline

(1)What is a Prime site for science-driven missions?

(2) Prime site from a geologically ancient perspective at regional scale

(3) Prime site from a geologically recent perspective at regional scale

(4) Prime site from a local perspective , which includes engineering specs, Trafficability, and traverse

(1) regional scale

(2) regional-local scale

(3) local scale

1000s k mancient

1000s k mrecent

10s k mancient

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What is a prime candidate site for MSL and other future science-driven International exploration?

It is a site that MSL can:

• “get to” based on current mission design,

• have optimal trafficability to perform “smart” reconnaissance for at least 20km(get the biggest bang for the buck)

It is a site that MSL can:

• traverse diverse (Prime) geologic terrains, which record diverse and far-reaching information:

• ancient to present geologic, sedimentologic, geochemical, paleohydrologic, paleoclimatic, and possible exobiologic (extant and/or fossilized life) information derived locally (aqueous/hydrothermal environments) and from great distances (catchment area)

Northern Slope Valleys (NSVs) is considered to be a Prime Target through a synthesis of existing Information (Tier-scalable geologic approach)

Odyssey, Mars Express, MRO

Northern Slope Valleys (NSVs) Prime Target• The NSVs region is located at a major break in slope

between Tharsis bulge, southern highlands, and northern plains.

MOLA

At regional scale and geologically ancient perspective, the NSVs is considered to be a Prime candidate site because it :

• archives a far-reaching stratigraphic record (Noachian to Amazonian rock materials; e.g., sedimentary capped volcanics), which includestime-stratigraphic markers

MOLA

Part of geologic map of the western equatorial region(Scott and Tanaka, 1986)

Geologic crosssection (Dohm et al., 2001)

• contains rock materials that may have sourced from the Noachian Thaumasia highlands mountain range (e.g., interpreted to be ancient metamorphic and basement complex; e.g., Scott and Tanaka, 1986) and Noachian-Amazonian basaltic and possibly silica-enriched volcanoes and lava flow fields

NSVsE W

3D MOLA-based oblique projection

Connerney et al., 2005

Extremely ancient geologic provenances that are marked by magnetic anomalies, including the ancient Thaumasia highlands mountain range

Ranges may also contain ancient hydrothermal deposits such as expected for Warrego rise in the Thaumasia highlands mountain range (Gulick, 1993; Dohm et al., 1998, 2001)

• records macrostructures (10s to 1000s km-long mapped from MOLA topography), including structurally-controlled releases of putative ground water and other volatiles

MOLA

• comprises a system of valleys that generally correspond spatially to gravity lows and occur within a large topographic depression (e.g., Phillips et al., 2001); the gravity lows may represent low-density materials that partly infill the valleys and large topographic depressions (Dohm et al., 2001)

Gravity (e.g., Yuan et al.,, 2001)

• occurs in a region that is marked by magnetic anomalies (in a region that records Noachian-Amazonian fluvial activity, which could have exposed ancient magnetized materials)

Crustal magnetization discovered by the Mars Global Surveyor MAG/ER experiment (e.g., Acuña et al.,, 2001)

• encapsulates at least three distinct paleohydrologic regimes: Noachian-Early Hesperian NSVs flooding (~108 - 1010 m3/sec), Late Hesperian-Early Amazonian Mangala Valles flooding (~107 m3/sec), Amazonian sapping channel formation such Abus Vallis (~103 m3/sec), and recent groundwater seeps (<102 m3/sec), all of which expose deposits for in-situ study by MSL and other science-driven mission architectures MOLA

MOC

At regional scale and geologically recent perspective, the NSVs Region is considered to be a Prime candidate site for MSL or other future International science-driven exploration of Mars because it occurs in a region of recent geologic and hydrogeologic activity

• occurs in a region elevated in chlorine and hydrogen (referred to it as the Tharsis/Elysium corridor region;Dohm et al., 2005,2006):

Unpublished GRS data from Bill Boynton and the rest of the GRS team submitted to JGR Planets(GRS-based JGR Planets Special Edition coming soon)

elevated hydrogen and chlorine could indicate aqueous activity (past and present), including interactions of magma with water/water-ice (unpublished GRS-based information).

Fairén et al., 2003

Catastrophic episodic outbursts of internal heat energy at Tharsisand elsewhere such as Elysium (Baker et al., 1991; Dohm et al., 2001; Fairén et al., 2003)triggers floods that inundate the northern plains to form bodies of water ranging from oceans (e.g., Parker et al. 1987;1993; Clifford and Parker, 2001) to lakes (Scott et al., 1995)and associated transientclimatic perturbations(10s to 100s of years; Bakeret al., 1991, 2001)

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Prime site from a local perspective , which includes engineering specs, Trafficability, and traverse

MOLA

THEMIS colorized

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Landing Sites…

Homing in on the

• Elevation ~ -2400 MOLA

defined elevation

Fine Scale MOLA

Elevation

Rock Abundance

Rock Abundance = >5

Surface Roughness

• Surface Roughness ranges from moderate to smooth

Radar and Stealth Zone Proximity

Edgett et al (1997)

Thermal Inertia

Need more data coverage !!!

Landing Ellipse

Dust ‘Free’ Area

Landing Area

Inverted channel

Possible alluvial fandeposits

Themis Visible

A visit to the crater would add ~2-4 km

Possible

• Strengths:– Geologically and hydrologically and interesting and varied

site.– Good extended mission track available for rover– Rover internal power source lessens the negative impact of

dust.– One of very few dust ‘free’ areas in NSV region.

• Weaknesses:– Region has a lot of dust– Extended mission would take rover into dusty area– Close to the “stealth zone"

• Threats:– Large rocks on ejecta blanket and/or alluvial fan– Turbulent high winds are possible???

Diverse information sets and theoretical prediction, (tier-scalable geologic approach leads to an increased probability) collectively point to the NSVs region as a prime target site for in-situ future geological, hydrological, sedimentological (paleosols), mineralogical, and biological investigations

Conclusion

Rover Instrumentation: Will the suite of instruments….?

• Laser Induced Remote Sensing for Chemistry and Micro-Imaging

• Gas Chromatograph Mass Spectrometer/Tunable Laser

Spectrometer• X-Ray Diffraction/X-Ray

Fluorescence Instrument• Alpha particle X-Ray

Spectrometer• Radiation Assessment

Detector• Pulsed Neutron Source

and Detector

Marsprogram.jpl MSL will travel 10s of kilometers?