Date of Award

January 2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Earth, Atmospheric, and Planetary Sciences

First Advisor

Henry J Melosh

Second Advisor

Andrew Freed

Committee Member 1

David Minton

Committee Member 2

Marc Caffee

Committee Member 3

James Richardson


4 Vesta, the second most massive asteroid in the Solar System, was the recent target of NASA’s Dawn mission, which spent many months orbiting and analyzing the body. A geologically young (~1 Ga) giant impact basin, Rheasilvia, which has a diameter nearly equal to that of Vesta, dominates Vesta’s southern hemisphere. In addition to opening a massive crater, the impact that formed the Rheasilvia basin produced a shockwave that was sufficiently strong to modify Vesta’s surface morphology on a nearly global scale.