Robert Pepin

Robert Pepin, Professor Emeritus

Robert Pepin

Professor Emeritus, School of Physics and Astronomy



Minnesota Institute for Astrophysics (MIfA)


Ph.D., University of California, Berkeley, 1964

A.B., Harvard College, 1956

Professional Background

  • Director, Institute of Technology Honors Program, 1989-2009
  • Director, Lunar Science Institute, Houston, 1974-77
  • Sigma Xi National Lecturer, 1970-71

Scientific & Professional Societies

  • Fellow, Meteoritical Society
  • Fellow, American Geophysical Union
  • Fellow, Geochemical Society and European Association for Geochemistry
Research Interests

Origin and early history of volatile elements and compounds in the solar system as revealed by mass spectrometer measurements of noble gases and nitrogen in meteorites, lunar samples, interplanetary dust particles, and comets. Areas of particular interest include the composition of the primordial solar nebula, isotopic signatures of nucleosynthesis in primitive meteorites, the compositional history of solar wind and flares over the past 4+ billion years, and the origin and evolution of volatiles in the interiors and atmospheres of Earth, Mars and Venus.

Honors and Awards

  • Fellow of the Geochemical Society and European Association for Geochemistry, 2007
  • Asteroid “robertpepin”, 2002
  • George Taylor Distinguished Service Award, 2001
  • Morse-Alumni Award for Outstanding Contributions to Undergraduate Education, 2000
  • Fellow of the American Geophysical Union, 1993
  • Fellow of the Meteoritical Society, 1980
  • NASA Medal for Exceptional Scientific Achievement, 1971

Selected Publications

  1. C. R. Webster et al., Isotope ratios of H, C, and O in CO2 and H2O of the Martian atmosphere., Science 341, 260-263 (2013)
  2. S. K. Atreya et al. , Primordial argon isotope fractionation in the atmosphere of Mars measured by the SAM instrument on Curiosity and implications for atmospheric loss., Geophys. Res. Lett. 40, 1-5, (2013).
  3. M. H. Wong et al. , Isotopes of nitrogen on Mars: Atmospheric measurements by Curiosity’s mass spectrometer., Geophys. Res. Lett. 40, 6033-6037 (2013)
  4. R. O. Pepin, R. L. Palma, R. D. Gehrz, and S. Starrfield, Presolar grains from novae: Evidence from neon and helium isotopes in comet dust collections., ApJ 742:86 (15pp), (2011).
  5. R. O. Pepin, D. J. Schlutter, R. H. Becker, and D. B. Reisenfeld, Helium, neon, and argon composition of the solar wind as recorded in gold and other Genesis collector materials., Geochim. Cosmochim. Acta 89, 62-80, (2012)
  6. B. Marty, R. L. Palma, R. O. Pepin, L. Zimmermann, D. J. Schlutter, P. G. Burnard, A. J. Westphal, C. J. Snead, S. Bajt, R. H. Becker, and J. Simones , Helium and neon abundances and isotopic compositions in cometary matter., Science 319, 75-78 (2008).
  7. P. R. Mahaffy et al. , Abundance and isotopic composition of gases in the Martian atmosphere from the Curiosity rover., Science 341, 263-266 (2013).