ASTEROIDAL COLLISION PROBABILITIES

Several past calculations of collision probabilities between pairs of bodies on independent orbits have yielded inconsistent results. We rev iew the methodologies and identify their various problems. Greenberg's (1982) collision probability formalism (now with a corrected symmetry assumption) is equivalent to Wetherill's (1967) approach, except that it includes a way to avoid singularities near apsides. That method sh ows that the procedure by Namiki and Binzel (1991) was accurate for th ose cases where singularities did not arise.