Understanding the Distribution of Near-Earth Asteroids
William F. Bottke Jr.,
1
Robert Jedicke,
2
Alessandro Morbidelli,
3
Jean-Marc Petit,
3
Brett Gladman
3
We have deduced the orbital and size distributions of
the near-Earth asteroids (NEAs) by (i) numerically integrating NEAs from their source regions to their observed orbits, (ii) estimating the
observational biases and size distribution associated with asteroids on
those orbits, and (iii) creating a model population that can be fit to
the known NEAs. We predict that there are ~900 NEAs with absolute
magnitude less than 18 (that is, kilometer-sized), of which 29, 65, and
6% reside on Amor, Apollo, and Aten orbits, respectively. These
results suggest that roughly 40% of the kilometer-sized NEAs have been
found. The remainder, on highly eccentric and inclined orbits, are more
difficult to detect.
1 Center for Radiophysics and Space Research,
Cornell University, Ithaca, NY 14853-6801, USA.
2 Lunar and Planetary Laboratory, University of
Arizona, Tucson, AZ 85721, USA.
3 Observatoire de la
Côte d'Azur, Boite Postale 4229, 06034 Nice Cedex 4, France.
To whom correspondence should be addressed. E-mail:
bottke{at}astrosun.tn.cornell.edu
