Satellites of the Outer Planets


Dr. Paul M. Schenk

Staff Scientist
Lunar and Planetary Institute, 3600 Bay Area Blvd., Houston, Texas 77058
281 486-2157
[email protected]


A space-groupie since Gemini days in the mid 1960's, my first formal introduction to planetary sciences was as a NASA Planetary Geology summer intern in 1979 at JPL during the Voyager 2 Jupiter encounter.  Working for Voyager during one of its encounters was an unforgettable experience.  (Since 1992 I have also been an intern advisor for LPI's summer intern program.)  In 1988 I completed my Ph.D. at Washington University in St. Louis under Dr. William B. McKinnon.  Since arriving at the LPI in 1991 I have been using Voyager, Galileo, and Cassini stereo and monoscopic images to map the topography and geology of the icy outer planet satellites (and dabbled a bit on Mars and the Moon).

I have also been a stereo image afficionado for many years, and in 1997 completed an educational/fun CD-ROM entitled 3-D Tour of the Solar System showing the planets in 3-D.  Other interests include 20th Century history, the Titanic, volleyball, stained glass, scuba, and deep sea diving (view this image with 3-D glasses!).

Research Activities

My research efforts focus on the geology and topography of the icy satellites of the outer planets and occasionally Mars.  Current activities include the study of impact crater morphology, distributions, and frequencies on Ganymede, Europa, and icy satellites in general.  I have also been using stereo images to map the topography of impact craters and resurfaced regions on the icy satellites, with special emphasis on Io, Europa, Ganymede, Enceladus, Dione, Triton, and soon Pluto, as well as the shape, topography, and origins of mountains and shield volcanos on Io.


Current Projects and Weblogs

Data Archives

Selected Discoveries

  • IO
    • Origin of mountains by vertical tectonism on Io (1998)
    • Bipolar distribution of mountains (and paterae on Io) (2001)
    • A deep lava channel on Io (2004)
    • "Plate tectonics" on Europa (1980, published 1989)
    • Constraint on the thickness of Europa's icy shell, from investigation of impact craters
    • Evidence for Polar Wander on Europa (2008)
    • Impact of tidally disrupted comets on the Galilean satellites (w/H. J. Melosh)
    • Topographic evidence for low-viscosity volcanism on Ganymede (2001)
    • Origin of large domes inside craters on Ganymede (1993)
    • Timing of viscous relaxation and high heat flow in Ganymede (in preparation)
    • Origin of cantaloupe terrain on Triton (diapirism) (1993)
    • Planetecentric origin of craters on Triton (and a very young surface age) (2007)
    • South polar topography of Mars (1999)
    • North polar topography on the Moon (2004)

Selected Papers

Schenk, P., Matsuyama, I., and Nimmo, F., Evidence for true polar wander on Europa from global scale small circle depressions, Nature, in press, 2008.

Schenk, P., and Zahnle, K., On the negligible surface age of Triton, Icarus, 192, 135-149, 2007.

Grundy, W., Schenk, P., and 14 others, New Horizons Mapping of Europa and Ganymede, Science, 318, 234-238, 2007.

Nimmo, F., and P. Schenk, Normal faulting on Europa, J. Struct. Geol., 28, 2194, 2006.

Schenk, P., and Bussey, B., Galileo Stereo Topography of the Lunar North Polar Region, Geophys. Res. Lett., L23701, 2004.

Schenk, P., and D. Williams, A Potential Thermal Erosion Lava Channel on Io, Geophys. Res. Lett., L23702, 2004.

Schenk, P., Pappalardo, R., Topographic variations in chaos on Europa: Implications for diapiric formation, Geophys. Res. Lett., 31, L16703, doi:10.1029/2004GL019978, 2004.

Moore, J., P. Schenk, L. Bruesch, E. Asphaug, and W. McKinnon, Large impact features on middle-sized icy satellites Icarus, 171, 421-443, 2004.

Schenk, P., R. Wilson, and A. Davies, Shield volcano topography and rheology of lava flows on Io, Icarus, 169, 98-110, 2004.

Zahnle, K., Schenk, P., Levison, H., and Dones, L., Cratering rates in the outer solar system, Icarus, 163, 263-289, 2003.

Moore, J., A. Howard, W. Dietrich, P. Schenk, Martian Layered Fluvial Deposits: Implications for Noachian Climate Scenarios, Geophys. Res. Lett., 30, PLA 6-1, DOI 10.1029/2003GL019002, 2003.

Schenk, P., Thickness constraints on the icy shells of the Galilean satellites from a comparison of crater shapes, Nature, 417, 419-421, 2002.

Schenk, P., and F. Ridolfi, Morphology and scaling of ejecta deposits on icy satellites, Geophys. Res. Lett., 29, 10.1029/2001GRL013512, 2002.

Schenk, P., R. Wilson, H. Hargitai, A. McEwen, and P. Thomas, The mountains of Io: Global and geologic perspectives from Voyager and Galileo, J. Geophys. Res., 106, 33201-33222, 2001.

Schenk, P., W. McKinnon, D. Gwynn, and J. Moore, Flooding of Ganymede's resurfaced terrains by low-viscosity aqueous lavas, Nature, 410, 57-60, 2001.

Schenk, P., and J. Moore, Stereo topography of the South Polar region of Mars: Volatile inventory and Mars Polar Lander landing site, J. Geophys. Res., 105, 24529-24546, 2000.

Schenk, P., and M. Bulmer, Origin of mountains on Io by thrust faulting and large-scale mass movements, Science, 279, 1514-1518, 1998.

Schenk, P., E. Asphaug, W. McKinnon, H. Melosh, and P. Weissman, Cometary nuclei and tidal disruption: The geologic record of crater chains on Callisto and Ganymede, Icarus, 121, p. 249-274, 1996.

Melosh, H.J., and P. Schenk, Split comets and the origin of crater chains on Ganymede and Callisto, Nature, 365, 731-733, 1993.

Schenk, P., and M. Jackson, Diapirism on Triton: A record of crustal layering and instability, Geology, 21, p. 299-302, 1993.

Schenk, P., Central pit and dome craters: Exposing the interiors of Ganymede and Callisto, J. Geophys. Res., 98, 7475-7498, 1993.

Schenk, P., and McKinnon, W., Dark ray and dark floor craters on Ganymede and the provenances of large impactors in the Jovian system, Icarus, 89, 318-346, 1991.

Schenk, P., Crater formation and modification on the icy satellites of Uranus and Saturn: Depth/diameter and central peak occurrence, J. Geophys. Res., 94, 3812-3832, 1989.

Schenk, P., and W. McKinnon, Fault offsets and lateral crustal movement on Europa: Evidence for a mobile ice shell, Icarus, 79, p. 75-100, 1989.

Schenk, P., and W. McKinnon, Dark halo craters and the thickness of grooved terrain on Ganymede, J. Geophysical Res., 90, suppl., C775-C783, 1985.

Schenk, P., and W. McKinnon, Dark halo craters and the thickness of grooved terrain on Ganymede, J. Geophys. Res., 90, C775-C783, 1985.

Selected Books/Chapters

Schenk, P., Chapman, C., Zahnle, K., Moore, J., Ages and Interiors, The cratering record of the Galilean Satellites, in Jupiter, (F. Bagenal, T. Dowling and W. McKinnon, eds.), Cambridge Press, pp. 427-456, 2004.

Schenk, P., Ice Moons of Sol, In Ice Worlds of the Solar System (P. Dasch, ed.), Cambridge Press, pp. 110-134, 2004.

Schenk, P., and J. Moore, Geologic landforms and processes on icy satellites, in Solar System Ices (B. Schmitt et al., Eds.), pp. 551-578, 1998.

Last updated
April 30, 2010