August 31, 2006: Rebecca M. E. Williams and David P. O’Brien, Research Scientists at the Planetary Science Institute, are among the first awardees of the prestigious NASA “Carl Sagan Fellowship for Early Career Researchers.” Only 12 people were selected for these fellowships in 2006.
Dr. Williams is being honored for her successful proposal to the NASA Mars Fundamental Research Program to study ancient riverbeds on Earth, exposed as elevated ridges in the United States and Australia, that may offer an explanation for similar curved raised features on Mars.
These features are preserved on the Earth when the riverbed is coated with a calcium carbonate cement or covered by lava, making a cast. The surrounding material is then lost by erosion, leaving behind the cast of the channel.
Dr. Williams will conduct field research to identify characteristics of these landforms that would allow them to be recognized from Mars orbit. In addition she will be evaluating models for estimating the flow of water through these ancient channels and then applying these models to the Martian landforms to determine how much water flowed through them for how long. This research will also give us a better understanding of when water was flowing on the surface of Mars.
Dr. O’Brien is being honored for his successful proposal to the NASA Planetary Geology and Geophysics Program to better understand the influence of collisions and gravitational interactions on the evolution of the solar system.
This includes exploring the collisional and dynamical environment of the primordial disk of planetesimals that existed beyond Neptune in the early solar system, and the imprint that has left in the modern population of Kuiper Belt objects and comets.
Dr. O’Brien will also study the effects of large random collisions on the evolution of the Jupiter Trojan population of asteroids. These asteroids form two large clouds that lead and trail Jupiter around its orbit, trapped in gravitational resonance with the planet. This work will provide insight into the differences in population between these two clouds.
Dr. O’Brien will also be working to understand the effects of Jupiter and Saturn on the formation and evolution of the asteroid belt, Earth and the terrestrial planets.
PSI will be receiving $690,000 over the next three years for Drs.Williams and O’Brien.
Contact information: 520-620-6300
Dr. David O’Brien – obrien [at] psi. edu
Dr. Rebecca Williams – williams [at] psi. edu