U.S.-France Cooperative Research: Computing the Real Hazard to the Earth from Comets and Asteroids

Southwest Research Institute, San Antonio TX

Investigators

Abstract

0128350 Bottke This three-year award supports U.S.-France collaboration in astronomy between William F. Bottke of the Southwest Research Institute and Alessandro Morbidelli of the Observatory of Nice. The project addresses the origin and evolution of near earth objects or NEOs, a population of asteroids and comets crossing or nearly crossing the Earth's orbit. Present knowledge of orbital and size distributions of the NEO population is limited, because the NEOs known to the Earth are biased by complicated observational selection effects and because only a modest fraction of the entire NEO population has been discovered. US and French researchers addressed the first problem through development of quantitative models of debiased orbital and absolute magnitude distribution of NEOs. This collaboration is extended to new problems: design of NEO surveys to determine how and where to find the most hazardous or hard to find NEOs; computation of frequency of impacts on Earth and other terrestrial bodies as a function of the impact energy; computation of the relative collision rate on the moon and terrestrial planets; and computation of the upper limits on long-period and Halley-type comet population. The French investigators bring to this collaboration expertise in asteroid and cometary dynamics and the physics of collision fragmentation. This is complemented by US expertise in fast integration codes; large scale numerical simulations and statistics on orbital evolution.