Orbital Dynamics


Kepler's laws of planetary motion turn out to be far from the last word on planetary orbits. Orbits change over time, some changes are slow and periodic, others are chaotic and dramatic; these determine the architecture of planetary systems. In orbital dynamics research, we seek to discover the past and future of planetary systems - the diverse effects of gravity that shape where and how planets form and how their orbits evolve in time. We study the orbital evolution of planetary and satellite systems, and small bodies (asteroids and comets), as well as interplanetary dust, in the solar system and in exo-planetary systems. We seek discovery and understanding of the dynamical transport processes of planetary materials across vast distances in space and over geologically long times. We study how Earth's habitability is affected by its orbital history, and how orbital dynamics shapes extra-terrestrial environments.


  • Dr. Kathryn Volk started as a new postdoc in our group, in July 2015.
  • Prof. Renu Malhotra gave a public talk about Pluto and the Kuiper belt, at the SETI Institute in Mountain View, CA; it is on YouTube: https://youtu.be/IPrV-UoOD08.
  • Youngmin JeongAhn defended his PhD. dissertation, "Orbital distribution of minor planets in the inner solar system and their impact fluxes on the Earth, the Moon and Mars", on May 1, 2015. He will begin his postdoc position at NCU in Taiwan in October 2015.
  • Professor Renu Malhotra elected to the National Academy of Sciences, April 2015.
  • Professor Renu Malhotra was elected to the American Academy of Arts & Sciences, April 2015.
  • Professor Rick Greenberg retired Spring 2015 to Emeritus status.
  • Professor Renu Malhotra is serving on the Science Advisory Committee for the LSST. Read about her thoughts for solar system science with the LSST.
  • Some of the orbital dynamics group attended the AAS-Dynamical Astronomy Division annual meeting, April 28-May 1, in Philadelphia, PA. See Professor Malhotra's presentation titled, "A few points on the dynamical evolution of the young solar system."
  • Christa Van Laerhoven defended her Ph.D. dissertation, "Multi-Planet Extra-Solar Systems: Tides and Classical Secular Theory" on April 16, 2014. Congratulations, Dr. Van Laerhoven! She is currently a postdoctoral researcher at the University of Toronto.
  • Kathryn Volk defended her Ph.D. dissertation, "Dynamical Studies of the Kuiper Belt and the Centaurs", on April 01, 2013. Congratulations, Dr. Volk! She is presently the CITA National Fellow at the University of British Columbia.
  • College of Science awards Kathryn Volk "Outstanding Graduate Student - Scholarship", April 2013.
  • College of Science awards Galileo Circle Scholarship to Sarah Morrison, April 2013.


Strom, R. G., Renu, M., Xiao, Z.-Y., Ito, T., Yoshida, F., Ostrach, L. R. R The inner solar system cratering record and the evolution of impactor populations 2015RAA....15..407S

JeongAhn, Y., Malhotra, R. The current impact flux on Mars and its seasonal variation 2015Icar..262..140J

Malhotra, R. The Mass Distribution Function of Planets 2015ApJ...808...71M

Su, K. Y. L., Morrison, S., Malhotra, R., Smith, P. S., Balog, Z., Rieke, G. H. Debris Distribution in HD 95086—A Young Analog of HR 8799 2015ApJ...799..146S

Morrison, S., Malhotra, R. Planetary Chaotic Zone Clearing: Destinations and Timescales 2015ApJ...799...41M

JeongAhn, Y., Malhotra, R. On the non-uniform distribution of the angular elements of near-Earth objects 2014Icar..229..236J

Rodigas, T. J., Malhotra, R., Hinz, P. M. Predictions for Shepherding Planets in Scattered Light Images of Debris Disks 2014ApJ...780...65R

Petrovich, C., Malhotra, R., Tremaine, S. Planets near Mean-motion Resonances 2013ApJ...770...24P

Volk, K., Malhotra, R. Do Centaurs preserve their source inclinations? 2013Icar..224...66V

Su, K. Y. L., Rieke, G. H., Malhotra, R., Stapelfeldt, K. R., Hughes, A. M., Bonsor, A., Wilner, D. J., Balog, Z., Watson, D. M., Werner, M. W., Misselt, K. A. Asteroid Belts in Debris Disk Twins: Vega and Fomalhaut 2013ApJ...763..118S

Volk, K., Malhotra, R. The effect of orbital evolution on the Haumea (2003 EL61) collisional family 2012Icar..221..106V

Belbruno, E., Moro-Martín, A., Malhotra, R., Savransky, D. Chaotic Exchange of Solid Material Between Planetary Systems: Implications for Lithopanspermia 2012AsBio..12..754B