Joint Astrophysics/Space Physics Seminar

October 13, 2017 - 11:00am
618 VAN

"Super Catastrophic Disruption of Asteroids at Small Perihelion Distances" by, Robert Jedicke, Ph.D., University of Hawaii, Institute for Astronomy

Abstract:  Most near-Earth objects (NEOs) originate in the main asteroid belt as small objects that drift via non-gravitational thermal forces into resonant escape routes that then push them onto planet-crossing orbits. The dynamics of how these objects evolve in the inner solar system is well understood and has been used to predict the orbital nature and size-frequency distribution of the NEO population. However, problems have emerged with existing NEO models as NEO discoveries have increased. For example, many NEOs should be on orbits that closely approach the Sun yet few have been discovered. In addition, even though the NEO population is roughly an even mix of low-albedo (<10%) and high-albedo (>10%) asteroids, the characterized NEOs with small perihelion distances show a strong preference for high albedos.  Our new NEO model shows that the deficit is likely produced by the super-catastrophic disruption of a substantial fraction of small and mid-sized NEOs when they reach perihelion distances of a few tens of solar radii.