64th Annual Meteoritical Society Meeting (2001) 5457.pdf IMPLICATIONS OF ASTEROIDAL SATELLITES. W.J. Merline1 and C.R. Chapman2, 1Southwest Research Institute ([email protected]), 2Southwest Research Institute ([email protected]) There has been a recent revolution in asteroid astron- strange objects like the highly elongated metallic ob- omy that may have important implications for meteor- ject Kleopatra and the recently discovered distant sat- ite parent bodies. In short, in the last 8 years, it has ellite of a Kuiper Belt Object, could be a remnant from been found that numerous asteroids are double bodies accretionary processes. or have small satellites orbiting about them. The first one to be discovered (the 1.8 km moonlet found by the In thinking about where meteorites come from, it Galileo spacecraft to be orbiting around 31 km-sized would help parent-body modelers to have a mental Ida during a 1993 flyby) could have been a fluke, since framework that includes the kinds of configurations the accepted theoretical perspective at the time was now being discovered and the potential processes these that such satellites would be very rare or absent. How- bodies have been through before delivering meteorites ever, we now know that at least several percent of to our collections. Certainly there are implications main-belt asteroids are binaries and that a large per- from the existence of asteroidal satellites for the char- centage of Earth-approaching asteroids are binaries. acter of rubble piles, exposure ages of asteroidal rocks, and so on. The existence of double impact craters on It is not known with certainty how these satellites are the Earth and other planets may now have a more natu- created, but it is likely to be due to several different ral explanation. processes. Small satellites of main-belt asteroids may result during the process of catastrophic disruption of a A final, and important, aspect of asteroidal satellites is parent body and reaccretion of the fragments into sev- that definitive study of their orbits, in the context of eral separate pieces, some of which may acquire satel- Kepler's Third Law and complementary astronomical lites in the process. Earth-approaching objects may observations, provide an opportunity for robustly de- become double as a result of a very different process, termining the bulk density of asteroids, much more namely tidal distortion and disruption of an inherent cheaply than utilizing a spacecraft flyby. A lot of re- rubble pile during close passage to Earth, Venus, or cent speculations about the implications of crude cal- other large body. Formation of the double main-belt culations of bulk densities for a few asteroids for the body 90 Antiope (two 85 km asteroids, separated by character of potential meteorite parent bodies will soon about 170 km, orbiting about a common barycenter) be buttressed by precise determinations. remains a major theoretical problem; but it, and other.