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C.M. Lisse (University of Maryland)
We present the results of an ongoing thermal infrared photometric imaging survey of the size and mass loss rate of comets. Here we compare our estimates of the expected lifetime versus dust loss to dynamical models of the orbital evolution of the short period comets, and the number of detected extinct cometary nuclei. From this we deduce the role of comets in the present day solar system, including the contribution of cometary dust to the interplanetary dust cloud and the evolution and fate of highly aged comets. Our results indicate that the short period comets do not become extinct by long term dust and gas loss; rather, they either turn-off due to thick mantle formation within 103 - 104 years and become ``asteroids", destructively disintegrate, dynamically evolve out of the solar system, impact the Sun, or fragment into unobservedly small meteoroids.
This work has been supported by grant NAG5-9006 from the NASA Planetary Astronomy Program.
The author(s) of this abstract have provided an email address for comments about the abstract: lisse@astro.umd.edu