Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids

Details Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids

May 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009dda....40.0602h&link_type=abstract

American Astronomical Society, DDA meeting #40, #6.02; Bulletin of the American Astronomical Society, Vol. 41, p.899

Astronomy and Astrophysics

Astrophysics

Scientific paper

Asteroids, since the formation of the solar system, are known to have experienced catastrophic collisions, which---depending on the impact energy---can produce a major disruption of the parent body and possibly give birth to asteroid families or binaries [1]. We present a general study of the final shape and dynamical state of asteroids produced by the re-accumulation process following a catastrophic disruption.
Starting from a cloud of massive particles (mono-disperse spheres) with given density and velocity distributions, we analyse the final shape, spin state, and angular momentum of the system from numerical integration of a N-body gravitational system (code pkdgrav [2]). The re-accumulation process itself is relatively fast, with a dynamical time corresponding to the spin-period of the final body (several hours). The final global shapes---which are described as tri-axial ellipsoids---exhibit slopes consistent with a degree of shear stress sustained by interlocking particles.
We point out a few results:
-the final shapes are close to those of hydrostatic equilibrium for incompressible fluids, preferably Maclaurin spheroid rather than Jacobi ellipsoids
-for bodies closest to the sequence of hydrostatic equilibrium, there is a direct relation between spin, density and outer shape, suggesting that the outer surface is nearly equipotential
-the evolution of the shape during the process follows a track along a gradient of potential energy, without necessarily reaching its minimum
-the loose random packing of the particles implies low friction angle and hence fluid-like behaviour, which extends the results of [3].
Future steps of our analysis will include feature refinements of the model initial conditions and re-accumulation process, including impact shakings, realistic velocity distributions, and non equal-sized elementary spheres.
References
[1] Michel P. et al. 2001. Science 294, 1696
[2] Leinhardt Z.M. et al. 2000. Icarus 146, 133
[3] Richardson D.C. et al. 2005. Icarus 173, 349

Affiliated with

Also associated with

No associations

Rating

Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Re-accumulation Scenarios Governing Final Global Shapes of Rubble-Pile Asteroids will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-808669