Two things fill the mind with ever new and increasing wonder and awe: the starry heavens above me and the moral law within me.

Immanuel Kant

41020 － 1077 A.D.

Less Grandiose GoalsLess Grandiose Goals

A Tale of Methane OutlineOutline

MarsMars OverviewOverview

CHCH44 on Mars on Mars

Gliese 436bGliese 436b ChemistryChemistry

Mars: Composition + EvolutionMars: Composition + Evolution

Isotopic FractionationIsotopic Fractionation

McElroy + Donahue 1972McElroy + Donahue 1972

McElroy 1972McElroy 1972

McElroy + Nier + Yung 1976McElroy + Nier + Yung 1976

Kass and Yung, Science 1995

Yung + Russell + Parkinson 2010Yung + Russell + Parkinson 2010

McElroy + Donahue 1972McElroy + Donahue 1972

McElroy 1972McElroy 1972

McElroy + Nier + Yung 1976McElroy + Nier + Yung 1976

Kass and Yung, Science 1995

Yung + Russell + Parkinson 2010Yung + Russell + Parkinson 2010

Gravity and EscapeGravity and Escape

Yung and DeMore, 1999

determines evolutiondetermines evolution

10

Isotopic FractionationIsotopic Fractionation

12

13

Escape and Rayleigh DistillationEscape and Rayleigh Distillation

Methane on MarsMethane on Mars

Methane on MarsMethane on Mars Spectroscopic detection Biological Production? Geochemical Sources?

Mumma et al. (2009)

16

Photon OH O(1D)

CH4 430 yr 665 yr 1090 yr

CH3D 431 yr 931 yr 1155 yr13CH4 430 yr 668 yr 1104 yr

Column Integrated Lifetimes for Martian Methane Isotopologues

Nair et al., ICARUS, 2005

21

22

Yung et al. 2010

Martian BiogeochemistryMartian Biogeochemistry

Martian Pathways: SerpentinizationMartian Pathways: Serpentinization

Neptune

Gliese 436b

Gliese 436b

27

2929

30

31

32

34

37

38

39

Planets have CH4

Comparative Study of Atmospheric Chemistry and

Evolution

Biological evolution may be occurring on Mars

Exoplanets are natural extensions of our solar system

Conclusions: Unifying ThemesConclusions: Unifying Themes

More Grandiose GoalsMore Grandiose Goals

Li et al. PNAS 2008

Habitable Zone

Are we alone?

OR

Are we not alone in the universe?

Either way it is profound

I have never looked upon ease and happiness as ends in themselves --- such an ethical basis I call the ideal of a pigsty ... The ideals which have guided my way, and time after time have given me the energy to face life, have been Kindness, Beauty, and Truth.

Einstein on himself

真善美原一體

翁玉林 詩 伊犁 圖

AcknowledgementsAcknowledgements

YungYung’’s Group at Caltech, especially s Group at Caltech, especially

King-Fai Li for graphicsKing-Fai Li for graphics

Tinetti (UCL UK)Tinetti (UCL UK)

Meadows (UW)Meadows (UW)

Liang (Taiwan) Liang (Taiwan)

NASA/JPLNASA/JPL

4747

48

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