Effect of rotational disruption on the size–frequency distribution of the Main Belt asteroid population

The size distribution of small asteroids in the Main Belt is assumed to be determined by an equilibrium between the creation of new bodies out of the impact debris of larger asteroids and the destruction of small asteroids by collisions with smaller projectiles. However, for a diameter less than 6 km we find that YORP-induced rotational disruption significantly contributes to the erosion even exceeding the effects of collisional fragmentation. Including this additional grinding mechanism in a collision evolution model for the asteroid belt, we generate size-frequency distributions from either an accretional (Weidenschilling, 2011) or an "Asteroids were born big" (Morbidelli, 2009) initial size-frequency distribution that are consistent with observations reported in Gladman et al. (2009). Rotational disruption is a new mechanism that must be included in all future collisional evolution models of asteroids.

[1]  P. Michel,et al.  Spin-up of rubble-pile asteroids: Disruption, satellite formation, and equilibrium shapes , 2012 .

[2]  Daniel J. Scheeres,et al.  DEM simulation of rotation-induced reshaping and disruption of rubble-pile asteroids , 2012 .

[3]  Harold F. Levison,et al.  LATE ORBITAL INSTABILITIES IN THE OUTER PLANETS INDUCED BY INTERACTION WITH A SELF-GRAVITATING PLANETESIMAL DISK , 2011 .

[4]  S. Weidenschilling.  Initial sizes of planetesimals and accretion of the asteroids , 2011 .

[5]  F. Marzari,et al.  Combined effect of YORP and collisions on the rotation rate of small Main Belt asteroids , 2011 .

[6]  A. V. Sergeev,et al.  Formation of asteroid pairs by rotational fission , 2010, Nature.

[7]  A. Nakamura,et al.  The shape distribution of boulders on Asteroid 25143 Itokawa: Comparison with fragments from impact experiments , 2010 .

[8]  Harold F. Levison,et al.  Asteroids Were Born Big , 2009, 0907.2512.

[9]  Robert Jedicke,et al.  On the asteroid belt's orbital and size distribution , 2009 .

[10]  F. Marzari,et al.  Computing the effects of YORP on the spin rate distribution of the NEO population , 2009 .

[11]  Petr Pravec,et al.  The asteroid lightcurve database , 2009 .

[12]  P. Michel,et al.  Rotational breakup as the origin of small binary asteroids , 2008, Nature.

[13]  D. Vokrouhlický,et al.  ANALYTIC THEORY FOR THE YARKOVSKY–O'KEEFE–RADZIEVSKI–PADDACK EFFECT ON OBLIQUITY , 2008 .

[14]  Daniel J. Scheeres,et al.  Rotational fission of contact binary asteroids , 2007 .

[15]  A. Fitzsimmons,et al.  Spin Rate of Asteroid (54509) 2000 PH5 Increasing Due to the YORP Effect , 2007, Science.

[16]  K. Holsapple.  Spin limits of Solar System bodies: From the small fast-rotators to 2003 EL61 , 2007 .

[17]  M. Kaasalainen,et al.  Acceleration of the rotation of asteroid 1862 Apollo by radiation torques , 2007, Nature.

[18]  Daniel J. Scheeres,et al.  Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW4 , 2006, Science.

[19]  J. Kawaguchi,et al.  The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa , 2006, Science.

[20]  D. Scheeres.  The dynamical evolution of uniformly rotating asteroids subject to YORP , 2006 .

[21]  William F. Bottke,et al.  THE YARKOVSKY AND YORP EFFECTS: Implications for Asteroid Dynamics , 2006 .

[22]  Robert Jedicke,et al.  Linking the collisional history of the main asteroid belt to its dynamical excitation and depletion , 2005 .

[23]  R. Greenberg,et al.  Steady-State Size Distributions for Collisional Populations: Analytical Solution with Size-Dependent Strength , 2003, 1407.3307.

[24]  Alessandro Rossi,et al.  Evolution of NEO rotation rates due to close encounters with Earth and Venus , 2003 .

[25]  D. Campbell,et al.  Binary Asteroids in the Near-Earth Object Population , 2002, Science.

[26]  D. Lamb,et al.  Solar System Objects Observed in the Sloan Digital Sky Survey Commissioning Data , 2001, astro-ph/0105511.

[27]  Petr Pravec,et al.  Fast and Slow Rotation of Asteroids , 2000 .

[28]  D. Rubincam,et al.  Radiative Spin-up and Spin-down of Small Asteroids , 2000 .

[29]  W. Benz,et al.  Catastrophic Disruptions Revisited , 1999, astro-ph/9907117.

[30]  P. N. Smith,et al.  The Properties of Fragments from Catastrophic Disruption Events , 1998 .

[31]  W. Hartmann,et al.  Meteorite Delivery via Yarkovsky Orbital Drift , 1998 .

[32]  Farquhar,et al.  Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby , 1997, Science.

[33]  P. Farinella,et al.  Wavy size distributions for collisional systems with a small-size cutoff , 1994 .

[34]  D. Scheeres.  Dynamics about Uniformly Rotating Triaxial Ellipsoids: Applications to Asteroids , 1994 .

[35]  M. Nolan,et al.  Velocity Distributions among Colliding Asteroids , 1994 .

[36]  P. Farinella,et al.  Collision rates and impact velocities in the Main Asteroid Belt , 1992 .

[37]  Francesco Marzari,et al.  Accretional evolution of a planetesimal swarm: 1. A new simulation , 1991 .

[38]  H. Wiesmann,et al.  Lunar and Planetary Science , 2006 .

[39]  Michael P. Wiper,et al.  Bayesian statistical analysis of asteroid rotation rates , 1999 .

[40]  H. Rickman,et al.  Evolution and source regions of asteroids and comets : proceedings of the 173rd colloquium of the international astronomical union, held in Tatranská Lomnica, Slovak Republic, August 24-28, 1998 , 1999 .

[41]  Francesco Marzari,et al.  Collisional Evolution of Asteroid Families , 1995 .