Orbital and temporal distributions of meteorites originating in the asteroid belt

Abstract— The recent discovery of the importance of Sun-grazing phenomena dramatically changed our understanding of the dynamics of objects emerging from the asteroid belt via resonant phenomena. The typical lifetimes of such objects are now expected to be <10 Ma, thus demanding a reassessment of our general picture of the meteorite delivery process. By analysing direct numerical integrations of ∼2000 test particles beginning in the v6, 3:1, and 5:2 resonances in the main belt, we have reexamined the orbital and temporal distribution of meteoroids that journey to Earth. Comparing the results with fireball data, we find that the orbital distribution of Earth-impacting chondrites is consistent with a steady-state injection of meteoroids into the 3:1 and v6, resonances. Because this is the most complete and unbiased data set concerning Earth-impacting meteoroids, the agreement leads us to believe that our model is accurate. The simulations predict a P.M. fall ratio for chondrites ∼14% lower than the observed value of ∼68%, which argues for a moderate bias being present in this statistic. Most interestingly, the typical meteorite transfer times predicted by our models are several factors lower than the typical chondrite exposure ages, which implies that these meteorites acquired most of their exposure in the main belt before entering the resonances. We discuss some processes that would allow such preexposure. The case of achondrites and iron meteorites is also briefly discussed.

[1]  M. Moons,et al.  The Resonant Structure of the Kuiper Belt and the Dynamics of the First Five Trans-Neptunian Objects , 1995 .

[2]  L. Schultz,et al.  Cosmic‐ray exposure ages of diogenites and the recent collisional history of the howardite, eucrite and diogenite parent body/bodies , 1997 .

[3]  H. Scholl,et al.  The nu6 Secular Resonance Region Near 2 AU: A Possible Source of Meteorites , 1991 .

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

[5]  Alessandro Morbidelli,et al.  Chaotic Diffusion and the Origin of Comets from the 2/3 Resonance in the Kuiper Belt , 1997 .

[6]  K. Marti,et al.  COSMIC-RAY EXPOSURE HISTORY OF ORDINARY CHONDRITES , 1992 .

[7]  George W. Wetherill,et al.  Which fireballs are meteorites? A study of the Prairie Network photographic meteor data , 1981 .

[8]  K. Marti,et al.  Collisional history of H chondrites , 1995 .

[9]  M. Moons Review of the dynamics in the Kirkwood gaps , 1996 .

[10]  J. Wasson Ungrouped Iron Meteorites in Antarctica: Origin of Anomalously High Abundance , 1990, Science.

[11]  Dynamics of comets in the outer planetary region. II. Enhanced planetary masses and orbital evolutionary paths. , 1997 .

[12]  G. Wetherill Solar System Sources of Meteorites and Large Meteoroids , 1974 .

[13]  Patrick Michel,et al.  The Location of Linear Secular Resonances for Semimajor Axes Smaller Than 2 AU , 1997 .

[14]  D. Fink,et al.  Complex exposure histories for meteorites with “short” exposure ages , 1997 .

[15]  H. Scholl,et al.  The three principal secular resonances ν5, ν6, and ν16 in the asteroidal belt , 1989 .

[16]  M. Bailey,et al.  Vesta fragments from v6 and 3:1 resonances: Implications for V‐type near‐Earth asteroids and howardite, eucrite and diogenite meteorites , 1997 .

[17]  Ian Halliday,et al.  The Innisfree Meteorite and the Canadian Camera Network , 1978 .

[18]  P. Brown,et al.  The orbit and atmospheric trajectory of the Peekskill meteorite from video records , 1994, Nature.

[19]  D. L. Rabinowitz,et al.  Are Main-Belt Asteroids a Sufficient Source for the Earth-Approaching Asteroids? , 1997 .

[20]  Alessandro Morbidelli Asteroid Secular Resonant Proper Elements , 1993 .

[21]  Andrea Milani,et al.  An Asteroid on the Brink , 1995 .

[22]  Ian Halliday,et al.  Detailed data for 259 fireballs from the Canadian camera network and inferences concerning the influx of large meteoroids , 1996 .

[23]  C. Tuniz,et al.  On the Bur Gheluai H5 chondrite and other meteorites with complex exposure histories , 1993 .

[24]  J. Burns,et al.  The Exchange of Impact Ejecta Between Terrestrial Planets , 1996, Science.

[25]  Harold F. Levison,et al.  Dynamical Lifetimes and Final Fates of Small Bodies: Orbit Integrations vs Öpik Calculations , 1999 .

[26]  G. Wetherill ASTEROIDAL SOURCE OF ORDINARY CHONDRITES , 1985 .

[27]  G. Wetherill Multiple cosmic-ray exposure ages of meteorites , 1980 .

[28]  P. Farinella,et al.  The Injection of Asteroid Fragments into Resonances , 1993 .

[29]  H. Beust,et al.  Mean-Motion Resonances as a Source for Infalling Comets toward β Pictoris , 1996 .

[30]  Harold F. Levison,et al.  Dynamical Lifetimes of Objects Injected into Asteroid Belt Resonances , 1997 .

[31]  J. Henrard,et al.  Secular resonances in the asteroid belt: Theoretical perturbation approach and the problem of their location , 1991 .

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

[33]  Harold F. Levison,et al.  The Long-Term Dynamical Behavior of Short-Period Comets , 1993 .

[34]  D. Rubincam,et al.  Asteroid orbit evolution due to thermal drag , 1995 .

[35]  D. Revelle A quasi-simple ablation model for large meteorite entry: theory vs observations , 1979 .

[36]  C. B. Moore,et al.  Atmospheric ablation in meteorites: A study based on cosmic ray tracks and neon isotopes , 1980 .

[37]  T. Gehrels,et al.  The Palomar-Leiden survey of faint minor planets , 1970 .

[38]  H. Melosh,et al.  Origin of the Spacewatch Small Earth-Approaching Asteroids , 1996 .

[39]  P. Farinella,et al.  Dynamical evolution of NEAs: Close encounters, secular perturbations and resonances , 1996 .

[40]  Jack Wisdom,et al.  Meteorites may follow a chaotic route to Earth , 1985, Nature.

[41]  G. Wetherill Dynamical relations between asteroids, meteorites and Apollo-Amor objects , 1987, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[42]  Giovanni B. Valsecchi,et al.  Asteroids falling into the Sun , 1994, Nature.

[43]  J. Wisdom,et al.  Symplectic maps for the N-body problem. , 1991 .

[44]  A. Nakamura,et al.  Velocity and spin of fragments from impact disruptions: I. An experimental approach to a general law between mass and velocity , 1992 .

[45]  P. Michel,et al.  Numerical experiments on the efficiency of second-order mixed-variable symplectic integrators for N-body problems , 1996 .

[46]  J. Lissauer,et al.  Orbital Stability of the Uranian Satellite System , 1997 .

[47]  C. Tuniz,et al.  Exposure history of the Torino meteorite , 1996 .

[48]  G. Hahn,et al.  Dynamics of planet-crossing asteroids: Classes of orbital behavior: Project SPACEGUARD , 1989 .

[49]  J. Arnold The origin of meteorites as small bodies. ii - the model. , 1965 .

[50]  P. Michel Effects of Linear Secular Resonances in the Region of Semimajor Axes Smaller Than 2 AU. , 1997 .

[51]  G. Wetherill Stone Meteorites: Time of Fall and Origin , 1968, Science.

[52]  I. Halliday Detection of a meteorite ``stream'': Observations of a second meteorite fall from the orbit of the Innisfree chondrite , 1987 .

[53]  G. W. Wetherill,et al.  Collisions in the asteroid belt , 1967 .