The Dust Tails of Comet Hale-Bopp: A Staff Renewal Project, 15-9088

Principal Investigator
Daniel C. Boice

Inclusive dates: 07/01/98 - 06/30/99

Background - With the apparition of comet Hale-Bopp in 1996-97, the structure of dust tails proved even more complex than had been assumed by previous researchers. The dust emission from the nucleus is very heterogeneous and time variable. Additional complications arose from the intricate rotational state of the nucleus. The variety of different materials that are contained in comet dust add even more complexity to its dynamics and hence to the structure of the dust tail. The dynamics of dust tails for particles of a constant size and uniform composition are reasonably well understood by the Finson and Probstein theory, but the dynamics of fragmenting particles and the formation of striae, a type of tail inhomogeneity, are still unsolved problems. The scientific goal of this project will be to attack these long-standing problems through sophisticated numerical modeling to analyze the wealth of excellent observations acquired recently at the National Astronomical Observatory of Japan (NAOJ, Tokyo) of comet Hale-Bopp with high spatial resolution that spans a large range in heliocentric distance.

Approach - The goals of the proposed program are to 1) develop a cometary dust tail model through extensive collaboration with Japanese researchers involved in complementary programs, 2) enhance existing research programs in support of comet modeling and data analysis and the Deep Space 1 mission, and 3) build a stronger working relationship with members of the Japanese cometary science community for future joint proposals, future participation in spacecraft missions to small bodies, and observing opportunities at the new NAOJ 8.3-meter Subaru telescope. To carry out the proposed work, a state-of-the-art computer code will be developed that includes expertise from existing SwRI models and that is constrained by high-resolution images of comet Hale-Bopp's dust tails. Using this new program, a variety of physical processes that effect structures in the tails can be evaluated to synthesize a better global understanding of cometary dust features.

Accomplishments - Dr. D. C. Boice has taken up residence at NAOJ in Tokyo, Japan, to collaborate with Dr. Jun-ichi Watanabe for one year. This project has resulted in the development of a state-of-the-art model of cometary dust features by coupling and enhancing two existing cometary codes.  Two peer-reviewed publications have been produced. Additional benefits realized from this work include a positive impact on the performance of several existing projects at SwRI, including the availability of the 8.3-meter Subaru telescope (the third largest  steerable telescope in the world) to obtain observations of the target comet and asteroid of the Deep Space 1 mission. A contract with the National Science Foundation to continue the collaboration with Dr. Watanabe and further apply the cometary dust code for interpretation and analysis of additional observations of comet Hale-Bopp has been funded.  

Space Sciences Program 1999 IR&D Home SwRI Home