Sean Marshall is a fifth year PhD student working with Professor Don Campbell on observations of near-Earth asteroids. Sean uses radar and infrared data to characterize asteroids' shapes, sizes, and other physical properties. He is also working to improve the procedure of determining the uncertainties in asteroid shape model parameters.
Sean is interested in near-Earth asteroids because they are largely unexplored, despite being some of Earth's nearest neighbors in space. There are thousands of asteroids, but only a few dozen have been studied in detail. Asteroids are also interesting because some of them can potentially hit the Earth. In order to be prepared for this possibility, it is important to study asteroids, since deflecting a potential impactor requires an understanding of its physical properties. Radar and infrared observations provide as much information about an asteroid as it is possible to get from Earth-based remote sensing. The only way to do better is with a rare (and expensive) spacecraft flyby.
Sean's favorite part of being a graduate student at Cornell is the opportunity to work with leaders in the field, both at Cornell and at other institutions. This has included multiple visits to Arecibo Observatory for asteroid radar observations.
Sean was awarded a NASA Earth and Space Science Fellowship (NESSF) in 2015. As an undergraduate, Sean attended Arizona State University and worked at the Mars Space Flight Facility, under the guidance of Professor Phil Christensen.
When not defending Earth from killer asteroids, Sean manages Cornell's Ask an Astronomer website. Outside of astronomy, Sean enjoys reading, exploring Ithaca's bicycle trails, and cheering for sports teams from Cornell University, Arizona State University, and the city of Philadelphia.