• Walsh, K. J.
• Michel, Patrick
• Richardson, Derek C.

Abstract

Recent work (Walsh and Richardson 2006, 2007) has shown that although tidal disruption of near-Earth asteroids (NEAs) can account for some of the observed binary NEAs, a second mechanism is required to explain their relatively high population percentage (about 15%; Pravec et al. 2006). Here we present results investigating whether gravitational aggregates with some cohesive strength can more easily form binaries following rotational disruption than can pure rubble piles without cohesion. Our model consists of an idealized rubble pile of equal-size rigid spheres coupled with an elastic strength law with a fixed strain cutoff limit. In the manner of Richardson et al. (2005), we explore a parameter space of initial shape and spin using a numerical code to model the subsequent evolution of hundreds of individual aggregates. We measure the spin limit for mass loss as a function of initial shape, the amount of mass loss in the case of disruption, and the efficiency of binary formation. We also characterize any binaries formed and compare with observed binary NEAs. Our initial findings will be presented. DCR and KJW acknowledge support from NSF grants AST0307549 and AST0708110. PM acknowledges support of the ESA Advanced Concepts Team on the basis of the Ariadna study 07/4111, "Asteroid Centrifugal Fragmentation." References: Pravec, P. et al. 2006. Icarus 181, 63. Richardson, D.C., Elankumaran, P., Sanderson, R.E. 2005. Icarus 173, 349. Walsh, K.J., Richardson, D.C. 2006. Icarus 180, 201. Walsh, K.J., Richardson, D.C. 2007. Icarus, in press.

Topics

• impedance spectroscopy
• strength