dynamical chaos and resonance interactions

Locations of planetary mean-motion resonances.

A lucid survey of chaotic dynamics in the solar system was given by Jack Wisdom in his 1987 Urey Prize Lecture.

dynamically peculiar objects

The range of interesting dynamics exhibited by asteroids is quite large. Here is a web page devoted to objects with interesting or peculiar dynamics.

See, e.g., Wiegert et al. regarding the asteroid known as 1986 TO. Be sure to visit this friendly, thoughtful, and informative web site, and don't miss their superb mpeg (4.6 MB) of 1986 TO's motion in a frame of reference rotating with the Earth — it's well worth the download wait!

Another peculiar object is 1996 PW, which appears to be an asteroid but happens to be on a near-parabolic orbit characteristic of comets from the Oort cloud. How can this be? Well, in the primordial solar nebula the outer planets (notably Jupiter) will have scattered planetesimals in their vicinity. Some of these scattered objects should have been ejected out into the realm of the Oort cloud. Hence, it's possible to have an asteroid on a long-period cometary orbit, and that may be what we're seeing with 1996 PW. This unusual object is described in a paper by Weissman and Levison.

Near-Earth Objects (NEOs)

Also known as near-Earth Asteroids, or NEAs

Trans-Neptunian Objects (TNOs)

These are quite different in origin than the inner solar system asteroids, most likely being a reservoir of short-period comets.

There is a separate TNO page.

meteorite sources

Dynamical instabilities in the main belt can pump up eccentricities to such an extent that some asteroids become Mars-crossers. If they surviver to evolve further, they then become Earth-crossers and therefore a source of meteorites. See Jack Wisdom's 1985 paper, which describes how chaos generated in the 3:1 Kirkwood gap by resonance interactions can drive asteroid debris into Earth-crossing orbits.

families and groupings

surface composition and chemistry

asteroid rotations

radar studies

High-power radar measurements of asteroids provide a wealth of information about physical properties and orbits. A very nice web site devoted to asteroid radar studies is the Asteroid Radar Research page, written and maintained by the world's foremost asteroid radar expert, Steven Ostro.

occultation studies

mass determination

Asteroid masses are, with only a few exceptions, very poorly known (See, e.g., Hilton et al., 1996. Hence, the masses of the main and Kuiper belts are poorly known. Amazingly, this is now the largest cause of uncertainty for planetary ephemerides.

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