How to detect another 10 trillion small Main Belt asteroids

Abstract

Estimates of the size distribution of Main Belt asteroids suggest that there is an undetected population of approximately 10 trillion objects in the meter-to kilometer-range. These small objects are highly diverse impact generated fragments of ancient asteroids. This vast and so far unexplored resource of small bodies holds a rich variety of information on the origin and evolution of our Solar System. Current Earth-based telescopes have, with a few exceptions, not been able to detect the faint and distant meter-sized asteroids in the Main Belt. Deep exposures cannot be used, unless the object can be tracked, which is not possible for an object in an unknown orbit. Small asteroids can be observed close up from a spacecraft but, so far, missions to the Main Belt have not had the ability to detect new small asteroids (with the exception of Dactyl, the kilometer-sized asteroid, that was found orbiting the much larger asteroid Ida). Due to the rapidly changing geometry, small asteroids can only be observed from a spacecraft for a very limited time, hence it is not possible to operate a spacecraft from the distant Earth and a fully autonomous mission is required. The technology required to build such spacecrafts does exist and has been tested in space. We have explored the scientific potential of deep space missions to detect and study small asteroids from spacecrafts traveling through the asteroid Main Belt.