People: Astrobiology Graduate Students

Nate Kaib
Astronomy

I received a B.S. in physics from Case Western Reserve University in 2002. Before being accepted to UW astronomy, I'd never heard of astrobiology. With an interest in planet formation, though, astrobiology has served as a way to broaden my research. The two astrobiology courses as well as the many seminar series have allowed me to get to know students and faculty outside my department as well as learn basic concepts in many other fields. In addition, while the astrobiology curriculum is certainly no substitute for PhD work in other fields, they have taught me how to pursue the questions in my own area of research that are most relevant to the astrobiology community as a whole.

My thesis project is to model the formation and comet production of the Oort Cloud, a huge halo of icy bodies surrounding the solar system. This cloud is occasionally perturbed by the gravity of passing stars causing the population of Earth-crossing comets to temporarily increase by up to 2 orders of magnitude, and this phenomenon may be a source of mass extinctions seen in the fossil record as well as a source of organics to the early Earth. Furthermore, because Oort Cloud orbits are sculpted by outside perturbations, the Sun's dynamical history in the Milky Way has left a footprint in the structure of this cloud. Modeling the formation of the Oort Cloud in different galactic environments and comparing the results to the real Oort Cloud allows us to constrain the history of our solar system in a galactic context.