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Harry Y. McSweenHarry Y. McSween

Chancellor's Professor
Planetary Geoscience

Department of Earth and Planetary Sciences
732 Strong Hall
1621 Cumberland Ave
Knoxville, TN 37996-1410

Phone: (865) 974-9805

Unlike most geologists, Hap McSween is drawn to rocks falling from the heavens rather than to those already underfoot. For the past three and a half decades NASA has funded his research on meteorites. He and his students and postdocs have characterized the mineralogy, petrology, and cosmochemistry of:

  • Chondrites, the most common type of meteorites falling to Earth – focus is on constraining and computer modeling of thermal metamorphism and aqueous alteration processes on asteroids
  • Shergottites and nakhlites, generally accepted to be rocks from Mars – focus is on understanding magmatic processes and their geologic context
  • Eucrites, diogenites, and howardites, igneous rocks from a differentiated asteroid – focus is on quantifying petrologic and spectral properties and applying them to the interpretation of Dawn spacecraft data for asteroid Vesta

Dr. McSween is co-investigator for the Mars Odyssey spacecraft mission, which is mapping the mineralogy and geochemistry of the Martian surface from orbit, the Mars Exploration Rovers which have analyzed rocks and soils at two landing sites, and the Dawn spacecraft mission, which began orbiting asteroid Vesta in 2011 and will subsequently explore Ceres, the largest asteroid.

Dr. McSween regularly teaches undergraduate and graduate courses in igneous and metamorphic petrology, cosmochemistry, and planetary science.

For more information about Hap McSween's research, click here.

The Citadel - B.S. Chemistry, l967

The University of Georgia - M.S. Geology, l969

Harvard University - Ph.D. Geological Sciences, l977


  • Balta J. B., M. E. Sanborn, A. Udry, M. Wadhwa and H. Y. McSween (2015) Petrology and trace-element geochemistry of Tissint, the newest shergottite fall. Meteorit. Planet. Sci. 50, 63-85.
  • McSween H. Y. (2015) Centennial Article: Petrology on Mars. Amer. Mineral. 100, 2380-2395.
  • Lunning N. G., H. Y. McSween, T. J. Tenner, N. T. Kita, and R. J. Bodnar (2015) Insights into the mantle of asteroid 4 Vesta from mineral fragments in meteorite breccias. Earth Planet. Sci. Lett. 418, 126-135.
  • Fedo C. M., McGlynn I. O. and H. Y. McSween (2015) Grain size and hydrodynamic sorting controls on the composition of basaltic sediments: Implications for the interpretation of martian soils. Earth Planet. Sci Lett., 423, 67-77.
  • Takir D., J. P. Emery, and H. Y. McSween (2015) Toward an understanding of phyllosilicate mineralogy in the outer main asteroid belt. Icarus 257, 185-193.
  • Ammannito E., M. C. DeSanctis, J. P. Combe, A. Frigeri, R. Jaumann, A. Longobardo, H. Y. McSween, E. Palomba, F. Tosi, C. A. Raymond, and C. T. Russell (2015) The vestan Rheasilvia basin at high spatial and spectral resolution. Icarus 259, 194-202.
  • Prettyman T. H., N. Yamashita, R. C. Reedy, H. Y. McSween, D. W. Mittlefehldt, J. S. Hendricks, and M. J. Toplis (2015) Concentrations of potassium and thorium within Vesta's regolith. Icarus 259, 39-52.
  • Beck A. W., D. J. Lawrence, P. N. Peplowski, T. H. Prettyman, T. J. McCoy, H. Y. McSween, M. J. Toplis, and N. Yamashita (2015) Using HED meteorites to interpret neutron and gamma ray data from asteroid 4Vesta. Meteorit. Planet. Sci. 50, 1311-1337.
  • Udry A., H. Y. McSween, R. L. Hervig, and L. A. Taylor (2015) Lithium isotopes and light lithophile element abundances in shergottites: Evidence for both magmatic degassing and subsolidus diffusion. Meteoriti. Planet. Sci. 51, 80-104.
  • Lunning N. G., K. C. Welten, H. Y. McSween, M. W. Caffee, and A. W. Beck (2015) Grosvenor Mountains 95 howardite pairing group: Insights into the surface regolith of asteroid 4 Vesta.  Meteorit. Planet. Sci. 51, 167-194.
  • De Sanctis M. C., E. Ammannito, A. Raponi, S. Marchi, T. B. McCord, H. Y. McSween, F. Capaccioni, M. T. Capria, G. Carrozzo, A. Longobardo, S. Fonte, M. Formisano, A. Frigeri, M. Giardino, G. Magni, E. Palomba, F. Tosi, D. Turrini, F. Zambon, J-P. Combe, T. Feldman, R. Jaumann, D. Lawrence, L. A. McFadden, C. M. Pieters, T. Prettyman, M. Toplis, C. A. Raymond, and C. T. Russell (2015) Ammoniated phyllosilicates with a likely outer Solar System origin on (1) Ceres. Nature 528, 241-244.

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