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James Roberts

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Planetary Geophysicist
240-228-9133
  • Ph.D., Astrophysical, Planetary, and Atmospheric Sciences
    2006, University of Colorado
  • M.S., Astrophysical, Planetary, and Atmospheric Sciences
    2003, University of Colorado
  • B.S., Physics
    2001, Virginia Polytechnic Institute and State University
  • B.S., Geological Sciences
    2001, Virginia Polytechnic Institute and State University

My goal is to understand why the various planets and moons of the solar system look the way they do now, what they were like early in their history, and how they evolved to their present state.  I approach these questions this by modeling large-scale geodynamics of terrestrial planets and icy satellites.  I am primarily concerned with:

  • Sources of heat in planetary interiors, tidal dissipation, radioactive decay, and impacts.
  • Solid-state convection and the removal of heat from planetary interiors.
  • Surface features and mass anomalies generated by geodynamic processes, and their effect on planetary reorientation.
  • The relationship between the thermal and orbital evolution of planets and moons.

The models are developed with the goal of explaining specific surface observations of targeted planetary bodies (e.g. Mars or Enceladus), but with appropriate parameters can be applied to planetary bodies in general.

Notable Awards and Leadership

Year(s) Description
2014 - Present Geological Society of America
2012 - Present Division of Planetary Sciences (affiliate)
2009 - Present Outer Planets Assessment Group
2001 - Present American Geophysical Union
2011 Editor’s Citation for Excellence in Refereeing, American Geophysical Union
2010 Johns Hopkins University Applied Physics Laboratory Publication Award
2004-2005 “Best Should Teach” Silver Award, Graduate Teacher Program, University of Colorado
2001-2003 Supplemental Fellowships, Department of Astrophysics and Planetary Science, University of Colorado

Scholarly Publications

Breaking the symmetry by breaking the ice shell: An impact origin for the south polar terrain of Enceladus

Icarus, 2021
James H. Roberts and Angela M. Stickle, (2021), Breaking the symmetry by breaking the ice shell: An impact origin for the south polar terrain of Enceladus, Icarus, 114302, https://doi.org/10.1016/j.icarus.2021.114302

Digital terrain mapping by the OSIRIS-REx mission

\planss, 2020
Barnouin, O.~S. and Daly, M.~G. and Palmer, E.~E. and Johnson, C.~L. and Gaskell, R.~W. and Al Asad, M. and Bierhaus, E.~B. and Craft, K.~L. and Ernst, C.~M. and Espiritu, R.~C. and Nair, H. and Neumann, G.~A. and Nguyen, L. and Nolan, M.~C. and Mazarico, E. and Perry, M.~E. and Philpott, L.~C. and Roberts, J.~H. and Steele, R.~J. and Seabrook, J. and Susorney, H.~C.~M. and Weirich, J.~R. and Lauretta, D.~S., (2020), Digital terrain mapping by the OSIRIS-REx mission, planss, 180, 104764

Shape of (101955) Bennu indicative of a rubble pile with internal stiffness

Nature Geoscience, 2019
Barnouin, O.~S. and Daly, M.~G. and Palmer, E.~E. and Gaskell, R.~W. and Weirich, J.~R. and Johnson, C.~L. and Al Asad, M.~M. and Roberts, J.~H. and Perry, M.~E. and Susorney, H.~C.~M. and Daly, R.~T. and Bierhaus, E.~B. and Seabrook, J.~A. and Espiritu, R.~C. and Nair, A.~H. and Nguyen, L. and Neumann, G.~A. and Ernst, C.~M. and Boynton, W.~V. and Nolan, M.~C. and Adam, C.~D. and Moreau, M.~C. and Rizk, B. and Drouet D'Aubigny, C.~Y. and Jawin, E.~R. and Walsh, K.~J. and Michel, P. and Schwartz, S.~R. and Ballouz, R. -L. and Mazarico, E.~M. and Scheeres, D.~J. and McMahon, J.~W. and Bottke, W.~F. and Sugita, S. and Hirata, N. and Hirata, N. and Watanabe, S. -I. and Burke, K.~N. and Dellagiustina, D.~N. and Bennett, C.~A. and Lauretta, D.~S. and Osiris-Rex Team, (2019), Shape of (101955) Bennu indicative of a rubble pile with internal stiffness, Nature Geoscience, 12, 4, 247-252

Modeling an exogenic origin for the equatorial ridge on Iapetus

ıcarus, 2018
Stickle, Angela M. and Roberts, James H., (2018), Modeling an exogenic origin for the equatorial ridge on Iapetus, icarus, 307, 197-206

Effects of basin-forming impacts on the thermal evolution and magnetic field of Mars

Earth and Planetary Science Letters, 2017
Roberts, J.~H. and Arkani-Hamed, J., (2017), Effects of basin-forming impacts on the thermal evolution and magnetic field of Mars, Earth and Planetary Science Letters, 478, 192-202

Mean radius and shape of Pluto and Charon from New Horizons images

ıcarus, 2017
Nimmo, Francis and Umurhan, Orkan and Lisse, Carey M. and Bierson, Carver J. and Lauer, Tod R. and Buie, Marc W. and Throop, Henry B. and Kammer, Josh A. and Roberts, James H. and McKinnon, William B. and Zangari, Amanda M. and Moore, Jeffrey M. and Stern, S. Alan and Young, Leslie A. and Weaver, Harold A. and Olkin, Cathy B. and Ennico, Kim, (2017), Mean radius and shape of Pluto and Charon from New Horizons images, icarus, 287, 12-29

Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour

Nature, 2016
William B. McKinnon, Francis Nimmo, Teresa Wong, Paul M. Schenk, Oliver L. White, J. H. Roberts, J. M. Moore, J. R. Spencer, A. D. Howard, O. M. Umurhan, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young, K. E. Smith, New Horizons Geology Geophys, (2016), Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour, Nature, 534, 7605, 82-+

Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour (vol 534, pg 82, 2016)

Nature, 2016
K. E. Smith, L. A. Young, C. B. Olkin, H. A. Weaver, S. A. Stern, O. M. Umurhan, A. D. Howard, J. R. Spencer, J. M. Moore, J. H. Roberts, Oliver L. White, Paul M. Schenk, Teresa Wong, Francis Nimmo, William B. McKinnon, (2016), Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour (vol 534, pg 82, 2016), Nature

The fluffy core of Enceladus

Icarus, 2015
James H. Roberts, (2015), The fluffy core of Enceladus, Icarus, 258, 54-66

The Pluto system: Initial results from its exploration by New Horizons

Science, 2015
S. A. Stern, F. Bagenal, K. Ennico, G. R. Gladstone, W. M. Grundy, W. B. McKinnon, J. M. Moore, C. B. Olkin, J. R. Spencer, H. A. Weaver, L. A. Young, T. Andert, J. Andrews, M. Banks, B. Bauer, J. Bauman, O. S. Barnouin, P. Bedini, K. Beisser, R. A. Beyer, S. Bhaskaran, R. P. Binzel, E. Birath, M. Bird, D. J. Bogan, A. Bowman, V. J. Bray, M. Brozovic, C. Bryan, M. R. Buckley, M. W. Buie, B. J. Buratti, S. S. Bushman, A. Calloway, B. Carcich, A. F. Cheng, S. Conard, C. A. Conrad, J. C. Cook, D. P. Cruikshank, O. S. Custodio, C. M. Dalle Ore, C. Deboy, Z. J. B. Dischner, P. Dumont, A. M. Earle, H. A. Elliott, J. Ercol, C. M. Ernst, T. Finley, S. H. Flanigan, G. Fountain, M. J. Freeze, T. Greathouse, J. L. Green, Y. Guo, M. Hahn, D. P. Hamilton, S. A. Hamilton, J. Hanley, A. Harch, H. M. Hart, C. B. Hersman, A. Hill, M. E. Hill, D. P. Hinson, M. E. Holdridge, M. Horanyi, A. D. Howard, C. J. A. Howett, C. Jackman, R. A. Jacobson, D. E. Jennings, J. A. Kammer, H. K. Kang, D. E. Kaufmann, P. Kollmann, S. M. Krimigis, D. Kusnierkiewicz, T. R. Lauer, J. E. Lee, K. L. Lindstrom, I. R. Linscott, C. M. Lisse, A. W. Lunsford, V. A. Mallder, N. Martin, D. J. McComas, R. L. McNutt, D. Mehoke, T. Mehoke, E. D. Melin, M. Mutchler, D. Nelson, F. Nimmo, J. I. Nunez, A. Ocampo, W. M. Owen, M. Paetzold, B. Page, A. H. Parker, J. W. Parker, F. Pelletier, J. Peterson, N. Pinkine, M. Piquette, S. B. Porter, S. Protopapa, J. Redfern, H. J. Reitsema, D. C. Reuter, J. H. Roberts, S. J. Robbins, G. Rogers, D. Rose, K. Runyon, K. D. Retherford, M. G. Ryschkewitsch, P. Schenk, E. Schindhelm, B. Sepan, M. K. Showalter, K. N. Singer, M. Soluri, D. Stanbridge, A. J. Steffl, D. F. Strobel, T. Stryk, M. E. Summers, J. R. Szalay, M. Tapley, A. Taylor, H. Taylor, H. B. Throop, C. C. C. Tsang, G. L. Tyler, O. M. Umurhan, A. J. Verbiscer, M. H. Versteeg, M. Vincent, R. Webber, S. Weidner, G. E. Weigle, O. L. White, K. Whittenburg, B. G. Williams, K. Williams, S. Williams, W. W. Woods, A. M. Zangari, E. Zirnstein, (2015), The Pluto system: Initial results from its exploration by New Horizons, Science, 350, 6258, 292-+

The low-degree shape of Mercury

Geophysical Research Letters, 2015
Mark E. Perry, Gregory A. Neumann, Roger J. Phillips, Olivier S. Barnouin, Carolyn M. Ernst, Daniel S. Kahan, Sean C. Solomon, Maria T. Zuber, David E. Smith, Steven A. Hauck, Stanton J. Peale, Jean-Luc Margot, Erwan Mazarico, Catherine L. Johnson, Robert W. Gaskell, James H. Roberts, Ralph L. McNutt, Juergen Oberst, (2015), The low-degree shape of Mercury, Geophysical Research Letters, 42, 17, 6951-6958

Could giant basin-forming impacts have killed Martian dynamo?

Geophysical Research Letters, 2014
W. Kuang, W. Jiang, J. Roberts, H. V. Frey, (2014), Could giant basin-forming impacts have killed Martian dynamo?, Geophysical Research Letters, 41, 22, 8006-8012

Impact heating and coupled core cooling and mantle dynamics on Mars

Journal of Geophysical Research-Planets, 2014
James H. Roberts, Jafar Arkani-Hamed, (2014), Impact heating and coupled core cooling and mantle dynamics on Mars, Journal of Geophysical Research-Planets, 119, 4, 729-744

Observational bias and the apparent distribution of ponds on Eros

Icarus, 2014
James H. Roberts, Olivier S. Barnouin, Eliezer G. Kahn, Louise M. Prockter, (2014), Observational bias and the apparent distribution of ponds on Eros, Icarus, 241, 160-164

Origin and flatness of ponds on asteroid 433 Eros

Meteoritics & Planetary Science, 2014
James H. Roberts, Eliezer G. Kahn, Olivier S. Barnouin, Carolyn M. Ernst, Louise M. Prockter, Robert W. Gaskell, (2014), Origin and flatness of ponds on asteroid 433 Eros, Meteoritics & Planetary Science, 49, 10, 1735-1748

Convection-driven compaction as a possible origin of Enceladus's long wavelength topography

Journal of Geophysical Research-Planets, 2013
J. Besserer, F. Nimmo, J. H. Roberts, R. T. Pappalardo, (2013), Convection-driven compaction as a possible origin of Enceladus's long wavelength topography, Journal of Geophysical Research-Planets, 118, 5, 908-915

Subcontinental sinking slab remnants in a spherical geometry mantle model

Journal of Geophysical Research-Solid Earth, 2013
S. Quere, J. P. Lowman, J. Arkani-Hamed, J. H. Roberts, R. Moucha, (2013), Subcontinental sinking slab remnants in a spherical geometry mantle model, Journal of Geophysical Research-Solid Earth, 118, 4, 1760-1777

Thermal evolution of Mercury as constrained by MESSENGER observations

Journal of Geophysical Research-Planets, 2013
Nathalie C. Michel, Steven A. Hauck, Sean C. Solomon, Roger J. Phillips, James H. Roberts, Maria T. Zuber, (2013), Thermal evolution of Mercury as constrained by MESSENGER observations, Journal of Geophysical Research-Planets, 118, 5, 1033-1044

Impact-induced mantle dynamics on Mars

Icarus, 2012
James H. Roberts, Jafar Arkani-Hamed, (2012), Impact-induced mantle dynamics on Mars, Icarus, 218, 1, 278-289

Sustainability of a subsurface ocean within Triton's interior

Icarus, 2012
Jodi Gaeman, Saswata Hier-Majumder, James H. Roberts, (2012), Sustainability of a subsurface ocean within Triton's interior, Icarus, 220, 2, 339-347

The effect of the Caloris impact on the mantle dynamics and volcanism of Mercury

Journal of Geophysical Research-Planets, 2012
James H. Roberts, Olivier S. Barnouin, (2012), The effect of the Caloris impact on the mantle dynamics and volcanism of Mercury, Journal of Geophysical Research-Planets, 117

Impact basin relaxation at Iapetus

Icarus, 2011
Guillaume Robuchon, Francis Nimmo, James Roberts, Michelle Kirchoff, (2011), Impact basin relaxation at Iapetus, Icarus, 214, 1, 82-90

Exposure of spectrally distinct material by impact craters on Mercury: Implications for global stratigraphy

Icarus, 2010
Carolyn M. Ernst, Scott L. Murchie, Olivier S. Barnouin, Mark S. Robinson, Brett W. Denevi, David T. Blewett, James W. Head, Noam R. Izenberg, Sean C. Solomon, James H. Roberts, (2010), Exposure of spectrally distinct material by impact craters on Mercury: Implications for global stratigraphy, Icarus, 209, 1, 210-223

Giant impacts on early Mars and the cessation of the Martian dynamo

Journal of Geophysical Research-Planets, 2009
J. H. Roberts, R. J. Lillis, M. Manga, (2009), Giant impacts on early Mars and the cessation of the Martian dynamo, Journal of Geophysical Research-Planets, 114

Near-surface heating on Enceladus and the south polar thermal anomaly

Geophysical Research Letters, 2008
J. H. Roberts, F. Nimmo, (2008), Near-surface heating on Enceladus and the south polar thermal anomaly, Geophysical Research Letters, 35, 9

Tidal heating and the long-term stability of a subsurface ocean on Enceladus

Icarus, 2008
James H. Roberts, Francis Nimmo, (2008), Tidal heating and the long-term stability of a subsurface ocean on Enceladus, Icarus, 194, 2, 675-689

Supercontinent cycles, true polar wander, and very long-wavelength mantle convection

Earth and Planetary Science Letters, 2007
Shijie Zhong, Nan Zhang, Zheng-Xiang Li, James H. Roberts, (2007), Supercontinent cycles, true polar wander, and very long-wavelength mantle convection, Earth and Planetary Science Letters, 261, 3-4, 551-564

The cause for the north-south orientation of the crustal dichotomy and the equatorial location of Tharsis on Mars

Icarus, 2007
James H. Roberts, Shijie Zhong, (2007), The cause for the north-south orientation of the crustal dichotomy and the equatorial location of Tharsis on Mars, Icarus, 190, 1, 24-31

Degree-1 convection in the Martian mantle and the origin of the hemispheric dichotomy

Journal of Geophysical Research-Planets, 2006
JH Roberts, SJ Zhong, (2006), Degree-1 convection in the Martian mantle and the origin of the hemispheric dichotomy, Journal of Geophysical Research-Planets, 111, E6

Plume-induced topography and geoid anomalies and their implications for the Tharsis rise on Mars

Journal of Geophysical Research-Planets, 2004
JH Roberts, SJ Zhong, (2004), Plume-induced topography and geoid anomalies and their implications for the Tharsis rise on Mars, Journal of Geophysical Research-Planets, 109, E3

On the support of the Tharsis Rise on Mars

Earth and Planetary Science Letters, 2003
SJ Zhong, JH Roberts, (2003), On the support of the Tharsis Rise on Mars, Earth and Planetary Science Letters, 214, 1-2, 1-9