PTYS/LPL Faculty

Kuiper 417


William Hubbard

Professor Emeritus

Exoplanets; Planetary Formation and Evolution, Planetary Atmospheres, Theoretical Astrophysics, Titan & Outer Solar System, Planetary interiors


Dr. Hubbard's research focuses on studies of the structure and evolution of Jupiter, Saturn, and extrasolar giant planets (EGPs). Originally as a Co-Investigator with the proposed INSIDE Jupiter orbiter and now as a Juno Co-Investigator, he showed how high-precision gravity data from a close-range Jupiter orbiter can be used to determine the depths to which Jupiter's extraordinary zonal wind patterns penetrate. Hubbard contributed to the 2013-2022 Planetary Sciences Decadal Survey of the US National Research Council as a member of the Giant Planet Panel. He is a Fellow of the American Astronomical Society, the American Geophysical Union, and the American Association for the Advancement of Science. He was awarded the 2005 Gerard P. Kuiper Prize in Planetary Sciences by the Division for Planetary Sciences of the American Astronomical Society. In collaboration with Burkhard Militzer at UC Berkeley, Hubbard is incorporating Militzer's first-principles density-functional equations of state for hydrogen-helium mixtures in models of Jupiter, Saturn, and EGPs. The models are matched to measurements of heat flow, mass, radius, and high-order gravity field (where known). One of the main objectives of the research is a determination of the metallicity of Jupiter and a validation of the standard cooling theory that is applied to EGPs.

In collaboration with the late Adam Showman (LPL) and Yohai Kaspi (Weizmann Inst.), Hubbard has analyzed the signature of interior dynamics on Jupiter's high-order gravity field.

The above projects are a component of Hubbard's research related to his role as a Co-Investigator on the Juno spacecraft, orbiting Jupiter since 2016.

View LPL Evening Lecture from September 8, 2015, Juno - Revealing Jupiter's Depths

Ph.D., 1967, Berkeley

Years with LPL: 1972 to present

Current Grants

  • Juno Science Support Phase E Activities, NASA

Current Spacecraft Involvement

  • Juno (NASA New Frontiers Jupiter orbiter mission), launched August 2011, en route to Jupiter with orbit insertion in 2016: Juno Mission

Former Spacecraft Involvement

  • INSIDE Jupiter Co-Investigator (low-periapse orbiter mission proposed under NASA Discovery Program, 1998 and 2001 cycles)
  • Maki Hattori, 2008 (M.S. PTYS)
  • Jonathan Fortney, 2004 (Ph.D. PTYS)
  • Robert Marcialis, 1990 (Ph.D. PTYS)
  • Mark Marley, 1990 (Ph.D. PTYS)
  • Joseph MacFarlane, 1983 (Ph.D. PTYS)
  • Wayne Slattery, 1976 (Ph.D. PTYS)

Former Postdocs

  • Tristan Guillot, 1995-1996
  • Didier Saumon, 1992-1994
  • George Horedt, 1982-1983


Complete publications list available from: NASA ADS Author search: William B. Hubbard

Refereed publications (NASA ADS): Calendar Year 2016 through July 2018

Guillot, T., Miguel, Y., Militzer, B., Hubbard, W. B., Kaspi, Y., Galanti, E., Cao, H., Helled, R., Wahl, S. M., Iess, L., Folkner, W. M., Stevenson, D. J., Lunine, J. I., Reese, D. R., Biekman, A., Parisi, M., Durante, D., Connerney, J. E. P., Levin, S. M., Bolton, S. J. A suppression of differential rotation in Jupiter’s deep interior 2018Natur.555..227G

Kaspi, Y., Galanti, E., Hubbard, W. B., Stevenson, D. J., Bolton, S. J., Iess, L., Guillot, T., Bloxham, J., Connerney, J. E. P., Cao, H., Durante, D., Folkner, W. M., Helled, R., Ingersoll, A. P., Levin, S. M., Lunine, J. I., Miguel, Y., Militzer, B., Parisi, M., Wahl, S. M. Jupiter’s atmospheric jet streams extend thousands of kilometres deep 2018Natur.555..223K

Iess, L., Folkner, W. M., Durante, D., Parisi, M., Kaspi, Y., Galanti, E., Guillot, T., Hubbard, W. B., Stevenson, D. J., Anderson, J. D., Buccino, D. R., Casajus, L. G., Milani, A., Park, R., Racioppa, P., Serra, D., Tortora, P., Zannoni, M., Cao, H., Helled, R., Lunine, J. I., Miguel, Y., Militzer, B., Wahl, S., Connerney, J. E. P., Levin, S. M., Bolton, S. J. Measurement of Jupiter’s asymmetric gravity field 2018Natur.555..220I

Robinson, T. D., Fortney, J. J., Hubbard, W. B. Analytic Scattering and Refraction Models for Exoplanet Transit Spectra 2017ApJ...850..128R

Bolton, S. J., Lunine, J., Stevenson, D., Connerney, J. E. P., Levin, S., Owen, T. C., Bagenal, F., Gautier, D., Ingersoll, A. P., Orton, G. S., Guillot, T., Hubbard, W., Bloxham, J., Coradini, A., Stephens, S. K., Mokashi, P., Thorne, R., Thorpe, R. The Juno Mission 2017SSRv..213....5B

Kaspi, Y., Guillot, T., Galanti, E., Miguel, Y., Helled, R., Hubbard, W. B., Militzer, B., Wahl, S. M., Levin, S., Connerney, J. E. P., Bolton, S. J. The effect of differential rotation on Jupiter's low-degree even gravity moments 2017GeoRL..44.5960K

Bolton, S. J., Adriani, A., Adumitroaie, V., Allison, M., Anderson, J., Atreya, S., Bloxham, J., Brown, S., Connerney, J. E. P., DeJong, E., Folkner, W., Gautier, D., Grassi, D., Gulkis, S., Guillot, T., Hansen, C., Hubbard, W. B., Iess, L., Ingersoll, A., Janssen, M., Jorgensen, J., Kaspi, Y., Levin, S. M., Li, C., Lunine, J., Miguel, Y., Mura, A., Orton, G., Owen, T., Ravine, M., Smith, E., Steffes, P., Stone, E., Stevenson, D., Thorne, R., Waite, J., Durante, D., Ebert, R. W., Greathouse, T. K., Hue, V., Parisi, M., Szalay, J. R., Wilson, R. Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft 2017Sci...356..821B

Wahl, S. M., Hubbard, W. B., Militzer, B., Guillot, T., Miguel, Y., Movshovitz, N., Kaspi, Y., Helled, R., Reese, D., Galanti, E., Levin, S., Connerney, J. E., Bolton, S. J. Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core 2017GeoRL..44.4649W

Wahl, S. M., Hubbard, W. B., Militzer, B. The Concentric Maclaurin Spheroid method with tides and a rotational enhancement of Saturn's tidal response 2017Icar..282..183W

Wahl, S. M., Hubbard, W. B., Militzer, B.  Tidal Response of Preliminary Jupiter Model 2016ApJ...831...14W

Militzer, B., Soubiran, F., Wahl, S. M., Hubbard, W.  Understanding Jupiter's interior 2016JGRE..121.1552M

Kaspi, Y., Davighi, J. E., Galanti, E., Hubbard, W. B.  The gravitational signature of internal flows in giant planets: Comparing the thermal wind approach with barotropic potential-surface methods 2016Icar..276..170K

Wisdom, J., Hubbard, W. B.  Differential rotation in Jupiter: A comparison of methods 2016Icar..267..315W

Hubbard, W. B., Militzer, B.  A Preliminary Jupiter Model 2016ApJ...820...80H

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Last updated on September 11, 2020