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Immanuel Kant
Two things fill the mind with ever
new and increasing wonder and
awe:
the starry heavens above me
and
the moral law within me.
1020－1077 A.D.
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Less Grandiose Goals
A Tale of Methane
Outline
 Mars
 Overview
 CH4
on Mars
 Gliese
436b
 Chemistry
Mars:
Composition + Evolution
Isotopic
Fractionation
McElroy + Donahue 1972
McElroy 1972
McElroy + Nier + Yung 1976
Kass and Yung, Science 1995
Yung + Russell + Parkinson 2010
Gravity and Escape
l determines evolution
Yung and DeMore, 1999
Isotopic Fractionation
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Escape and Rayleigh Distillation
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Methane
on Mars
Methane on Mars
 Spectroscopic
detection
 Biological Production?
 Geochemical Sources?
Mumma et al. (2009)
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Column Integrated Lifetimes for
Martian Methane Isotopologues
Photon
OH
O(1D)
CH4
430 yr
665 yr
1090 yr
CH3D
431 yr
931 yr
1155 yr
13CH
4
430 yr
668 yr
1104 yr
Nair et al., ICARUS, 2005
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Martian Biogeochemistry
Yung et al. 2010
Martian Pathways: Serpentinization
Gliese 436b
Neptune
Gliese 436b
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Conclusions: Unifying Themes
 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
More Grandiose Goals
Habitable Zone
Li et al. PNAS 2008
Are we alone?
OR
Are we not alone in the universe?
Either way it is profound
Einstein on himself
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.
真善美原一體
翁玉林 詩 伊犁 圖
Acknowledgements

Yung’s Group at Caltech, especially
King-Fai Li for graphics

Tinetti (UCL UK)

Meadows (UW)

Liang (Taiwan)

NASA/JPL
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Backup Slides
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