KEVIN ZAHNLE - NASA AMES RESEARCH CENTER

MS 245-3, Moffett Field, CA  94035
Phone:  650-604-0840     Fax:  650-604-6779     Email:  kzahnle@mail.arc.nasa.gov

Title and Role

Co-Investigator - An authority on the physics and consequences of large impacts as well as planet and planetary atmosphere evolution, Dr. Zahnle will be responsible for the studies involving whether impacts created the Martian valley river networks, and the runaway greenhouse studies for Mars and Venus-like planets.

Related Experience Summary

Photochemical modelling; geochemical modelling of atmophiles; impact processes (both ab initio modelling and data-driven modelling); impact frequencies; atmospheric escape processes; planetary accretion.

Employment History

NASA Ames Research Center 1988-present
Stanford University 1987-1988 (postdoc)
NRC (postdoc) at NASA Ames 1985-1987

Education

PhD University of Michigan 1985 (Prof. James C. G. Walker)

Awards and Honors

1996: NASA Exceptional Scientific Achievement Medal.
2001: Ames Associate Fellow

Selected Relevant Publications

K. Zahnle and J. C. G. Walker (1982).  "Evolution of solar ultraviolet luminosity."  Rev. Geophys. Space Phys. 20, 280–292.

K. Zahnle (1986).  "Photochemistry of methane and the formation of hydrocyanic acid (HCN) in the Earth's early atmosphere."  J. Geophys. Res. 91, 2819–2834.

K. Zahnle, J. Kasting, and J. Pollack (1988).  "Evolution of a steam atmosphere during Earth's accretion."  Icarus 74, 62–97.

N. Sleep, K. Zahnle, J. Kasting, and H. Morowitz (1989).  "Annihilation of ecosystems by large asteroid impacts on the early Earth."  Nature 342, 139–142.

K. Zahnle (1990).  "Atmospheric chemistry by large impacts."  In Global Catastrophes in Earth History, eds. V. Sharpton and P. Ward, G.S.A. Special Paper 247, 271–288.

K. Zahnle & N. H. Sleep (1997).  "Impacts and the early evolution of life."  In Comets and the Origin of Life, P. Thomas, C. Chyba, & C. McKay, eds, Springer-Verlag, pp. 175-208.

N. H. Sleep & K. Zahnle (2001).  "Carbon dioxide  cycling and implications for climate on ancient Earth." J. Geophys. Res. 106, 1373-1399.

N. H. Sleep, K. Zahnle and P. S. Neuhoff (2001).  "Initiation of clement surface conditions on the earliest Earth." Proc. Nat. Acad. Sci. 98, 3666-3672.

T. Segura, O.B. Toon, A. Colaprete, & K. Zahnle (2002).  "Environmental effects of large impacts on Mars." Science 298, 1977-1980.

D. C. Catling, C.P. McKay, & K. Zahnle (2001).  "Biogenic methane, hydrogen escape, and the irreversible oxidation of the early Earth." Science 293, 839-843.

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