Shown below is the distribution of asteroids in semimajor axis, eccentricity space contained in the inner solar system. Major groups are shown in the labeled boxes and include the Hungaria, Cybele, Hilda, and Trojan Groups. Also shown are the main-belt zones and the Flora family. Semimajor axis spans from Earth (at 1 AU) to just beyond Jupiter (at 5.2 AU). Mars is at 1.52 AU.

The groups and families shown in this diagram collect asteroids of similar dynamic characteristics. Some of these groups may have formed from the disruption of larger "parent" asteroids (for example, the Flora familiy and Hilda group). In other cases, asteroids are concentrated in dynamically stable regions (for example, the Trojan, Hungaria, and Cybelle groups).

This graph was created in June 2007 using all asteroids with "well-determined" orbits (specifically 159366 numbered asteroids). Orbital element extents/limits were taken as defined in the reference listed below (exception: eccentricity limit of the Hilda Group was increased from 0.3 to 0.35).

A Postscript version of this plot is also available.

References

1. Gradie, J. C.; Chapman, C. R.; and Tedesco, E. F. (1989) "Distribution of Taxonomic Classes and the Compositional Structure of the Asteroid Belt". In Asteroids II (R. P. Binzel, T. Gehrels, and M. S. Matthews, Eds.), p. 321, Univ. of Arizona Press, Tucson.