3. 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

4. 4 1020 － 1077 A.D.

5. Less Grandiose Goals

6. A Tale of MethaneOutline  Mars  Overview  CH 4 on Mars  Gliese 436b  Chemistry

7.  Mars: Composition + Evolution  Isotopic Fractionation McElroy + Donahue 1972 McElroy 1972 McElroy + Nier + Yung 1976 Kass and Yung, Science 1995 Yung + Russell + Parkinson 2010 McElroy + Donahue 1972 McElroy 1972 McElroy + Nier + Yung 1976 Kass and Yung, Science 1995 Yung + Russell + Parkinson 2010

8. Gravity and Escape

9. Yung and DeMore, 1999 determines evolution determines evolution

10. 10 Isotopic Fractionation

12. 12

13. 13 Escape and Rayleigh Distillation

14.  Methane on Mars

15. Methane on Mars  Spectroscopic detection  Biological Production?  Geochemical Sources? Mumma et al. (2009)

16. 16

17. PhotonOHO( 1 D) CH 4 430 yr665 yr1090 yr CH 3 D431 yr931 yr1155 yr 13 CH 4 430 yr668 yr1104 yr Column Integrated Lifetimes for Martian Methane Isotopologues Nair et al., ICARUS, 2005

21. 21

22. 22

23. Yung et al. 2010 Martian Biogeochemistry

25. Martian Pathways: Serpentinization

26. Neptune Gliese 436b

27. 27

29. 29

30. 30

31. 31

32. 32

34. 34

37. 37

38. 38

39. 39

40. 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 Themes

41. More Grandiose Goals

42. Li et al. PNAS 2008 Habitable Zone

43. Are we alone? OR Are we not alone in the universe? Either way it is profound

44. 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

45. 真善美原一體 翁玉林 詩 伊犁 圖

46. Acknowledgements  Yung’s Group at Caltech, especially King-Fai Li for graphics  Tinetti (UCL UK)  Meadows (UW)  Liang (Taiwan)  NASA/JPL

47. 47

48. 48 Backup Slides