In the past decade, new observations and new research tools have afforded us a better understanding of the interrelationships between comets and asteroids. The extensive automated surveys for near-Earth objects (NEOs) have serendipitously discovered many objects in comet-like orbits. Dynamical simulation codes have improved to the point where we can simulate the detailed orbital behavior of large swarms of test particles as they move out from various storage reservoirs, such as the Oort cloud and the Kuiper belt. Physical studies of both comets and asteroids have given us a far better understanding of the nature of these bodies and have identified possible discriminators to be used in comparing them. As a result, we can now identify likely dormant or extinct comet candidates among the asteroid population. It appears that ~6 ± 4% (or perhaps more) of the NEO population is derived from Jupiter-family comets. Also, it is highly likely that many asteroids in eccentric orbits with large semimajor axes and large inclinations are derived from the Oort cloud. However, we must also recognize that some small fraction of the Oort cloud population is likely to consist of asteroidal bodies ejected there during the clearing of the planetary zones in the early solar system. Additional physical and dynamical studies are required to continue improving our knowledge of the interrelationships between comets and asteroids and to help identify likely extinct comet candidates.
- Pub Date:
- March 2002