Close Encounters with Large Asteroids in the Next 50 Years

Abstract

A combined method of searching for asteroid close encounters has been described and applied for detection of close encounters with largest asteroids in a period of 50 years starting from 1991. The method consists of a multistep selection procedure and an accurate numerical integration and provides the parameters of close encounters with high reliability. We compiled a list of 208 close encounters with asteroids larger than 100 km in diameter occuring at distances less than 0.01 AU. Expected mutual perturbing effects have been computed for the most interesting pairs. Measurable effects, enabling an asteroid mass determination, have been found for three of the examined pairs (1, 1393; 4, 2831; 10, 2061), whereas smaller effects, requiring an improved observational accuracy, better orbital fits, and more reliable ephemerides, were detected in several other cases.