mumma_110504.1 detection and mapping of methane and water on mars: evidence for intense local...

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Detection and mapping of Methane and Water on Mars:Evidence for intense local enhancements in Methane.

Michael J. MummaGoddard Center for Astrobiology

NASA GSFC

Robert A. Novak (Iona College)Michael A. DiSanti (NASA GSFC)

Boncho P. Bonev (Univ. of Toledo at GSFC)Neil Dello Russo (CUA at GSFC)

Tilak Hewagama (Univ. of Maryland at GSFCMichael Smith (NASA GSFC)

Why is Earth WET ? (and ALIVE?)

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Mars was WET -

Was it also alive?

Is it now alive?

HST: Mars in 1995

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Long-slit mapping of Methane and Water on Mars

Long-slit mapping of Methane and Water on Mars

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Methane and Water on Mars

Klassen et al. Icarus 138:36-48 (1999)

Methane and Water on MarsUT 20.8 March 2003 (Ls = 155o)

S.E. lat = -7.4o, long = 275-325o

7.0 arc-sec diameter

NASA/IRTF CSHELL0.5 arc-sec slit

WFPC2 Image: 1 May 1999 (Ls = 132o)S.E. lat = +19o, long = 285o

STSCI-PRC99-27D (Bell, Wolff, et al.)mjm_111704.7

CSHELL slit position 20 March 2003

H2O

-- |------ |--CH4 R1

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Methane and Water on Mars

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Wavenumber, cm-1

Methane and Water on MarsUT 8.4 May 2003 Ls = 181o

S.E. lat = 17.5o S, long = 58-85o W10.0 arc-sec diameter

Image: UT 9.24 May 2003S.E. long = 42o WACS-030509-658-502-435J. Bell and M. Wolff

Sub-solar point

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Gemini South/Phoenix0.17 arc-sec slit

CH4 ---------|-----------------------------------------------------------------------------|----

H2O ---|----------|-------------------|---------------|---------

R1 R0

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Methane and Water on MarsGemini-South/Phoenix 8 May 2003 Ls = 181o : CML 58-85o W

Difference spectrum: 25º N - 18º S

slit position

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Methane on Mars: Gemini-South/Phoenix 8 May 2003 CML 58-85o W

Wavenumber, cm-1Wavenumber, cm-1

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Methane and Water on Mars

<——Hellas basin——>

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Methane and Water on Mars

<——Hellas basin——>

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Methane and Water on Mars

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Methane and Water on Mars CML 304o

Methane and Water on Mars

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<——Valles Marineris——>

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Methane and Water on MarsCH4 on Mars : Present work; Formisano et al. (PFS); Krasnopolsky et al. (CFHT);

Its presence requires ongoing recent release (300 yr photochemical lifetime).

This Work: Two CH4 spectral lines (R0, R1) are detected. Quantitative abundances agree.Quiescent levels range from 20 ppb to 60 ppb (at high latitudes).Two regions of major enhancement are found: 250 ppb and (up to) 800 ppb.

Discrete source regions are needed.The production/release mechanism is related to temperature.A more-efficient destruction mechanism may be implied (gas-grain chemistry?)

Possible abiotic origins of locally released methane:Geothermal activity (ala serpentization on Earth) - no supporting evidence. Test by Cx.Release of methane hydrate (from juvenile Mars?) - why now? Test by D/H ratio.

Possible biotic origin of locally released methane:Methanogens? - test by 13C/12C ratio in CH4; higher order organics.Release of methane hydrate (from deep biosphere?) - Test by D/H ratio.

Next steps: Firm up spatial variations - analyze additional maps, acquire additional data. Examine dependence on season, temperature, correlation with water, etc.Conduct in situ studies: orbital (e.g., MARVEL, OOO-2), airplane (e.g., ARES), landers.

End

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Methane and Water on Mars

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Methane and Water on Mars

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Methane and Water on Mars