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Linda Spilker

Photo of Linda Spilker


4800 Oak Grove Drive
M/S 230-205

Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Science Division

Research Fellow


Dr. Linda Spilker is a planetary scientist at NASA’s Jet Propulsion Laboratory who has participated in NASA and international planetary missions for over four decades.  Her mission roles have grown to encompass mission leadership as well as design, planning, operation and scientific data analysis.  As Cassini Project Scientist, Spilker led a team of over 300 international scientists to maximize the scientific return of the Cassini mission within cost and schedule.  She worked in a science role on the Cassini project for 30 years, and was a Co-I with the Cassini Composite Infrared Spectrometer (CIRS) team. She led the CIRS ring team focusing on thermal infrared studies and modeling of Saturn’s rings to address questions of the rings’ origin and evolution. She led the science preparation of two Cassini Senior Review Proposals, in 2012 and 2014, both of which received Excellent ratings. 

Spilker previously worked on Voyager for 12 years, as the Experiment Representative (science liaison to the project) with the Infrared Radiometer and Spectrometer (IRIS) team and as a science associate with the Photopolarimeter Team.  Prior to that she was a research assistant (as L. Horn) in the Geology Department at Caltech studying the lead and bismuth distribution in meteorite samples, with a focus on carbonaceous chondrites and early solar system history and formation.

Spilker currently serves on the Outer Planets Assessment Group (OPAG) Steering Committee as the Vice Chair for OPAG.  She was recently the Chair for the Division for Planetary Sciences (DPS).  She is very familiar with the 2012 Decadal Survey, provided input for Cassini and planetary ring science and was an author or coauthor on a number of white papers.  She has also participated on the Advisory Council for Planetary Data System Ring-Moon Systems Node since 1990, providing input on archiving data from Cassini and other planetary missions.


  • B.A. in Physics, California State University, Fullerton (1977)
  • M.S. in Physics, California State University, Los Angeles (1983)
  • Ph.D. in (summa cum laude), Geophysics and Space Physics UCLA (1992)

Professional Experience

Jet Propulsion Laboratory (1977-present)

Project Work

  • Cassini Project Scientist (2010 - Present)
  • Enceladus Life Finder Proposal Project Scientist, Discovery and NF (2014 – 2018)
  • Cassini Deputy Project Scientist (1997 - 2010)
  • Cassini Mission Scientist (1990 - 1997)
  • Cassini CIRS Investigation Scientist (1990 - 1992)
  • Cassini Assistant Study Scientist (1988 - 1990)
  • Hermes Discovery Mission Proposal Deputy Principal Investigator (1993 - 1998)
  • Voyager IRIS Experiment Representative (1979 - 1990)
  • Voyager IRIS Assistant Experiment Representative (1977 - 1979)

Science Work

  • Cassini Composite Infrared Spectrometer (CIRS) Co-Investigator (1990 - present)
  • Visiting Scientist at University of Paris 7 (2001, 2010)
  • Principal Investigator, Cassini Data Analysis Program (CDAP) (2009 - 2012 )
  • Principal Investigator for Ring Structure and Dynamics, OPR (2004 - 2006)
  • Principal Investigator for Planetary Ring Studies in PG&G (1993 - 1997, 1999 - 2002)
  • Co-Investigator on Coherent backscatter opposition effect in PG&G (1990 - 1997)
  • Co-Investigator on compositional mapping of Io using mutual satellite occultations (1990 - 1991)
  • Voyager Photopolarimeter (PPS) Science Associate (1984 - 1990)
  • Voyager Infrared Radiometer & Spectrometer (IRIS) Science Associate (1988 - 1990)

Research Assistant, Geology Department, California Institute of Technology (1975 - 1977)

Research Interests

  • Thermal infrared studies of Saturn's rings to address questions of ring evolution
  • Numerical modeling of gravitational waves and wakes in Saturn's rings to estimate local surface mass density and ring mass 
  • Acquisition and interpretation of Cassini Composite Infrared Spectrometer (CIRS) data to determine ring dynamics from thermal behavior as a function of solar and ring geometry

Selected Awards

  • JPL Voyager Award (2020)
  • NASA Outstanding Public Leadership Medal, Cassini Project Scientist (2018)
  • Cal State University Fullerton Alumna of the Year Award (2018)
  • JPL Magellan Award (2018)
  • The Women’s International Film and Television Showcase (The WIFTS) Foundation - Visionary Award (2017)
  • JPL Voyager Award (2016)
  • JPL Magellan Award (2014)
  • NASA Exceptional Service Medal, Cassini Project Scientist and Deputy Project Scientist (2013)
  • NASA Exceptional Service Medal, Voyager IRIS Neptune Encounter (1990) 
  • NASA Group Achievement Awards (15)  2002 - 2018
    • Cassini Jupiter Flyby Team (2000)
    • Cassini CIRS Team (1998)
    • Cassini Public Outreach (1998)
    • Voyager Photopolarimeter Science (1987)
    • Seven (7) NASA Group Achievement Awards for Voyager Mission (1982 - 1989) 
  • Distinguished Alumna Award from California State University, Fullerton (2005) 
  • Hall of Fame Award, Placentia-Yorba Linda Unified School District (1999) 
  • ESA Award for contribution to Huygens Probe (1997) 
  • Distinguished Alumna Award for Natural & Social Sciences from California State University at Los Angeles (1996)
  • California State University Fullerton Dept. of Physics Faculty Prize for Scholarship (1977)

Selected Publications

  1. Spilker, L., Cassini-Huygens Exploration of the Saturn system:  thirteen years of discovery. Science, Vol. 364, Issue 6445, 1046-1051, DOI: 10.1126/science.aat3760.
  2. Spilker, L. J., 2019. Cassini's Final Year at Saturn: Science Highlights and Discoveries. Geophysical Research Letters, 46, 11, 5754-5758.
  3. Tiscareno, M., Nicholson, P., Cuzzi, J., Spilker, L., Murray, C., Hedman, M., Colwell, J., Burns, J., Brooks, S., Clark, R., Cooper, N., Deau, E., Ferrari, C., Filacchione, G., Jerousek, R., LeMouelic, S., Showalter, M., Badman, S., Baker, E., Burratti, B., Baines, K., Sotin, C.   Remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale. Science, 364, Issue 6445, DOI: 10.1126/science.aau1017
  4. Flandes, A., Garcia, A., Spilker, L., Deau., E.   Ray-tracing thermal modeling of Saturn’s main rings. Icarus, 312, 157-171, (2018).
  5. Spilker, L. The Scientific Achievements of the Cassini-Huygens mission. 2018.  Serendipities in the Solar System and Beyond. ASP Conference Series, Vol. 513, proceedings of a conference held 10-13 July 2017 at National Central University, Taiwan. Edited by Chung-Ming Ko, Chan-Kao Chang, and Po-Chieh Yu. San Francisco: Astronomical Society of the Pacific, 2018, 131- 150.
  6. Dougherty, M. and Spilker, L.   Review of Saturn’s icy moons following the Cassini mission.  IOP Reports on Progress in Physics, Vol. 81, No. 6, 1-20.  DOI: 10.1088/1361-6633/aabdfb
  7. Spilker, L., Ferrari, C., Altobello, N., Pilorz, S., & Morishima, R. 2018. Thermal Properties of Rings and Ring Particles. In M. Tiscareno & C. Muray (Eds.), Planetary Ring Systems: Properties, Structure, and Evolution (Cambridge Planetary Science, pp. 399-433). Cambridge: Cambridge University Press. Doi: 10.1017/9781316286791.015
  8. Morishima, R.; Spilker, L.; Brooks, S.; Deau, E.; Pilorz, S.. Incomplete cooling down of Saturn's A ring at solar equinox: Implication for seasonal thermal inertia and internal structure of ring particles.    52 pages, 19 figures, Icarus in press; doi:10.1016/j.icarus.2015.06.025.
  9. Altobelli, N.; Lopez-Paz, D,; Pilorz, S.; Spilker, L..; Morishima, R.; Brooks, S.; Leyrat, C.; Deau, E.; Edgington, S.; Flandes, A.   Two numerical models designed to reproduce Saturn ring temperatures as measured by Cassini-CIRS.  2014.  Icarus, Volume 238, 205-220.
  10. Morishima, R., Spilker, L., Turner, N., 2014. Azimuthal temperature modulations of Saturn's A ring caused by self-gravity wakes. Icarus 228, 247-229.
  11. Spilker, L., C. Ferrari, R. Morishima. Saturn’s ring temperatures at equinox.  2013, Icarus 226, 316-322.
  12. Morishima, R., Spilker, L., Edgington, S. Regolith grain sizes of Saturn's rings inferred from Cassini-CIRS far-infrared spectra.  Icarus, Volume 222, Issue 2, 888-899.
  13. Christophe, B, L. Spilker, J.D. Anderson, N. Andre et al. OSS (Outer Solar System): a fundamental and planetary physics mission to Neptune, Triton and the Kuiper Belt. 2012. Experimental Astronomy, Volume 34, Issue 2, 203-242.
  14. Morishima, R., Spilker, L., Ohtsuki, Keiji.  A multilayer model for thermal infrared emission of Saturn's rings III: Thermal inertia inferred from Cassini CIRS.  2011, Icarus, Volume 215, Issue 1, 107-127.
  15. Morishima, R., L. Spilker, H. Salo, K. Ohtsuki, N. Altobelli, S. Pilorz. A multilayer model for thermal infrared emission of Saturn's rings II: Albedo, spins, and vertical mixing of rings. 2010, Icarus, Volume 210, Issue 1, 330-345.
  16. Flandes, A., Spilker, , R. Morishima, S. Pilorz, C. Leyrat, N. Altobelli, S. Brooks, S. Edgington, Brightness properties of Saturn's rings with decreasing solar elevation, 2010, Planetary and Space Science, Volume 58, Issue 13, 1758 - 1765.
  17. Cuzzi, J.N., J. A. Burns, S. Charnoz, R. N. Clark, J. E. Colwell, L. Dones, L. W. Esposito, G. Filacchione, R. G. French, M. M. Hedman, S. Kempf, E. A. Marouf, C. D. Murray, P. D. Nicholson, C. C. Porco, J. Schmidt, M. R. Showalter, L. Spilker, J. N. Spitale, R. Srama, M. Sremčević, M. S. Tiscareno, J. Weiss. An Evolving View of Saturn's Dynamic Rings. 2010. Science, Volume 327, 1470 -
  18. Cuzzi, J, R. Clark, G. Filacchione, R. French, R. Johnson, E. Marouf, Spilker. Ring Particle Composition and Size Distribution, 2009, in M. Dougherty, L. Esposito and T. Krimigis, eds., Saturn from Cassini-Huygens, Dordrecht, Springer, ISBN 978-1-4020-9216-9, 459 - 509.
  19. Altobelli, N., L. Spilker, C. Leyrat, S. Pilorz, S. Edgington, A. Flandes, Thermal phase curves observed in Saturn's main rings by Cassini CIRS. Vol. 36, L10105, 2009.
  20. Ferrari, C., Brooks S., Edgington S., Leyrat C., Pilorz S. and Spilker L., Structure of self-gravity wakes in Saturn's A ring as measured by Cassini CIRS, 2009, Icarus, Volume 199, Issue 1, 145-153.
  21. Spilker, L. Saturn Revolution. 2008. Astronomy 36, No. 10, 34 - 39.
  22. Altobelli, N., L. Spilker, C. Leyrat, S. Pilorz, 2008. Thermal observations of Saturn's main rings by Cassini CIRS: Phase, emission and solar elevation dependence, Planetary and Space Science, 56, 134-146.
  23. Leyrat, C., L. Spilker, N. Altobelli, S. Pilorz, C. Ferrari, 2008. Infrared observations of Saturn's rings by Cassini CIRS : Phase angle and local time dependence, Planetary and Space Science, 56 (2008) 117-133.
  24. Altobelli, N., Spilker, S. Pilorz, S. Brooks, S. Edgington, B. Wallis, M. Flasar, 2007. C ring fine structures revealed in the thermal infrared, Icarus, 191, 691-701.
  25. Spilker, L. J., S. H. Pilorz, B. D. Wallis, J. C. Pearl, J. N. Cuzzi, S. M. Brooks, N. Altobelli, S. G. Edgington, M. Showalter, F. M. Flasar, C. Ferrari, C. Leyrat, 2006. Cassini Thermal Observations of Saturn's main rings: Implications for particle rotation and vertical mixing, Planetary and Space Science, 54, Issue 12, 1167-1176.
  26. Spilker, L.J. 2006. Close Encounters with Saturn. 2006 Science Year, World Book, Inc., 12-27. Lead Article.
  27. Miner, E.D., Matson, D. L., and Spilker, L.J. Cassini at Saturn: The First Results. Chapter 9 in Solar System Update, Praxis Publishing, Ltd., 217 - 249.
  28. Spencer, J. R.; J. C. Pearl, M. Segura, F. M. Flasar, A. Mamoutkine, P. Romani, B. J. Buratti, A. R. Hendrix, L. J. Spilker, R. M. Lopes, 2006. Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot. Science, Vol. 311, Issue 5766, 1401-1405.
  29. Spilker, L., S. Pilorz, B. Wallis, S. Edgington, S. Brooks, J. Pearl, J., F. Flasar, 2005. Cassini CIRS Observations of a Roll-off in Saturn Ring Spectra at Submillimeter Wavelengths. Earth, Moon and Planets, Volume 96, Issue 3-4, 149-163.
  30. Spilker, L.J., S. Pilorz, A.L. Lane, R.M. Nelson B. Pollard, and C. T. Russell. 2004. Saturn A ring surface mass densities from spiral density wave dispersion behavior. Icarus 171, 372 - 390.
  31. Flasar, F.M., ...J. Spilker, and Cassini CIRS team. 2004. Exploring the Saturn System in the thermal infrared: The Composite Infrared Spectrometer. Space Science Rev., Vol. 114, Nos. 1-4, Kluwer Academic Publishers, 169-297.
  32. Spilker, L.J., C. Ferrari, J. Cuzzi, M. Showalter, J. Pearl and B. Wallis. 2003. Saturn's Rings in the Thermal Infrared. Planetary and Space Science (Special Issue: Surfaces and Atmospheres of the Outer Planets, their Satellites and Ring Systems), Vol. 51, Issues 14-15, 929-935.
  33. Matson, D.L., J. Spilker and J-P. Lebreton. 2003. The Cassini/Huygens Mission to the Saturnian System. The Cassini-Huygens Mission, Vol. 1, Space Sci. Rev., Vol. 104, Nos. 1-4, Kluwer Academic Publishers, 1-58.
  34. Cuzzi, J. N., J. E. Colwell, L. W. Esposito, C. C. Porco, C. D. Murray, P. D. Nicholson, L. J. Spilker, E. A. Marouf, R. C. French, N. Rappaport, and D. Muhleman 2003. Saturn's Rings: Pre-Cassini Status and Mission Goals. The Cassini-Huygens Mission, Vol. 1, Space Sci. Rev., Vol. 104, Nos. 1-4, Kluwer Academic Publishers, 191-208.
  35. Horn, L.J., 1997, Planetary rings, in Encyclopedia of Planetary Sciences, ed. J.H. Shirley and R.W. Fairbridge, Chapman & Hall, 602-607.
  36. Horn, L.J. and J.N. Cuzzi. 1996. Characteristic wavelengths of irregular structure in Saturn's B ring. Icarus, 119, 285-310.
  37. Horn, L.J., M.R. Showalter, and C.T. Russell. 1996. Detection and behavior of Pan wakes. Icarus, 124, 663-676.
  38. Horn, L.J., R.M. Nelson, W.D. Smythe, and B.W. Hapke. 1996. Coherent backscatter opposition effect from Saturn ring particles and their regoliths. Physics, Chemistry and Dynamics of Interplanetary Dust, ASP Conference Series, Volume 104, Bo A.S. Gustafson and Martha S. Hanner, eds., pp. 443-446.
  39. Horn, L.J., Ed. 1996 Cassini/Huygens: A Mission to the Saturnian System. SPIE2803.
  40. Hui, J., L. J. Horn, and A.L. Lane. 1991. Particle sizes of the Uranian delta ring's inner diffuse companion through comparison of RSS and PPS Voyager occultation data. Icarus, 93, 347-353.
  41. Colwell, J.E., J. Horn, A.L. Lane, L.W. Esposito, P.A. Yanamandra-Fisher, S.H. Pilorz, K.E. Simmons, M.D. Morrison, C.W. Hord, R.M. Nelson, B.D. Wallis, R.A. West, and B.J. Buratti. 1990. Voyager photopolarimeter observations of Uranian ring occultations. Icarus, 83, 102-125.
  42. Horn, L.J., J. Hui, A.L. Lane, and J.E. Colwell. 1990. Observations of Neptunian rings by the Voyager photopolarimeter. GRL, 17(10), 1745-1748.
  43. Horn, L.J., P.A. Yanamandra-Fisher, L.W. Esposito, and A.L. Lane. 1988. Physical properties of Uranian delta ring from a possible density wave. Icarus, 76, 485-492.