Micrometeoroid Impacts on Spacecraft: Can Asteroidal and Cometary Dust be Distinguished?

Both cometary and asteroidal sources should contribute to the population of micrometeoroids (MM) reaching Earth [1,2], although there is debate as to their relative numbers. Small impact features on spacecraft surfaces returned from low Earth orbit (LEO) can provide sufficient evidence to distinguish some, but certainly not all, impacts from these dust sources. In this paper we review the difficulties in attributing a source to MM impactors.