A systematic investigation of the validity of small-body thermal models through a combined analysis of infrared and radar measurements

Johns Hopkins University, Baltimore MD

Investigators

Abstract

AST-0808064 Vervack This project will systematically investigate the validity of the small-body thermal models used to determine size and albedo information. The commonest models generally assume a spherical geometry and small phase angles. Continued advances in infrared capabilities, including the Spitzer Space Telescope and the Stratospheric Observatory For Infrared Astronomy (SOFIA), are increasing the observational data at a rapid pace, which makes it imperative to assess quantitatively the effect of those assumptions. This project will investigate possible biases through combined analysis of infrared and radar observations of a number of asteroids. Realistic shape models derived from the radar observations will be used to calculate a more accurate thermal emission model, and comparing shape-based models to the most common thermal models provides a quantitative analysis of the biases those models introduce into the size and albedo estimates. In particular, this work will examine whether more realistic shapes will reduce the biases, and will derive a more representative thermal phase function for small, irregular bodies. The impact of this research is far reaching, including helping with proper mitigation of the hazard of Earth impact by asteroids and comets. Numerous educational opportunities for students at all levels and for teachers will be actively pursued, including involvement in mentoring and internship vehicles already in place at The Johns Hopkins University's Applied Physics Laboratory. The Arecibo Observatory regularly engages students, and conducts both student and teacher workshops. There will also be opportunities to involve students at small universities and colleges that otherwise might not get to participate in a large research project.