Paul Helfenstein

Visiting Scientist, CCAPS

Research Focus

Cassini Imaging Science Subsystem (ISS) Team. Investigations of surface geology of planetary surfaces, especially the icy satellites of outer planet satellites. Development and application of radiative transfer theory as a tool for remotely determining the surface physical properties of planets, natural satellites, asteroids, and comets.


  • Helfenstein, P. and M.K. Shepard (2011). Testing the Hapke Model: Improved Inversion and the Porosity Correction. Icarus 10.1016/j.icarus.2011.07.002.
  • Shepard, M.K. and P. Helfenstein (2011). A Laboratory Study of the Bidirectional Reflectance from Particulate Samples. Icarus (in press).
  • Souchon, A.L., Pinet, P.C., Chevrel, S.D., Daydou, Y.H., Baratoux, D., Kurita, K., Shepard, M.K., Helfenstein, P. (2011). An experimental study of Hapke’s modeling of natural granular surface samples. Icarus, 10.1016/j.icarus.2011.06.023.
  • Miller, C., A.J. Verbiscer, A. J., N.J. Chanover, N. J., J.A. Holtzman, and P. Helfenstein (2011). Comparing Phoebe's 2005 opposition surge in four visible light filters. Icarus 212, p. 819-834.
  • Spencer, J.R., Barr, A.C., Esposito, L.W., Helfenstein, P., Ingersoll, A.P., Jaumann, McKay, C.P., Nimmo, F., Waite, J.H, (2009). Enceladus: An Active Cryovolcanic Satellite; In Saturn after Cassini-Huygens (Chapter 22, Dougherty, M. K., Esposito, L. W., & Krimigis, S. M., Eds.) , Springer-Verlag. 683–724.
  • Shepard, M. K. and P. Helfenstein (2007). A test of the Hapke photometric model, J. Geophys. Res. 112, E03001, doi:10.1029/2005JE002625, 17pp.

Courses - Spring 2022