http://www.space.com/scienceastronomy/solarsystem/comet_missing_020620.html
Solving the Case of the Missing Comets By Robert Roy Britt space.com 20 June 2002 Astronomers know where most newly discovered comets come from, a reservoir on the outskirts of our solar system called the Oort Cloud, which extends nearly halfway to the next star. Now and then, one of these distant comets is booted into the inner solar system and loops around the Sun on its first close pass. Most of these first-time comets are then kicked clear out beyond the Oort Cloud, never to return. A smaller number are swallowed by the Sun. The remainder are set on a new course that will bring them back around the Sun in anywhere from 20 years to a million years, depending on their new orbits. Yet in the five decades that scientists have known all this, they have puzzled over why they don't see hundreds of times more returning comets than they do. The answer may be that the objects simply disintegrate, according to a new study. Full story here: http://www.space.com/scienceastronomy/solarsystem/comet_missing_020620.html
