Investigation of evolution of orbits similar to that of (4179) Toutatis

by Wm. Robert Johnston
page last modified 2 November 2008

Note: this report represents my senior research project in astronomy at the University of Texas at Austin, under the supervision and instruction of Art Whipple. It was completed May 1994.)


This project compared the orbital evolution of asteroid (4179) Toutatis to that of several fictitious asteroids in similar orbits. The nominal orbit of Toutatis along with orbits with varying initial values of inclination and eccentricity were numerically integrated for a period of 10,000 years. A limited run of 1,500 years using the nominal orbit for Toutatis but with a different timestep confirmed the effect of its highly chaotic behavior on attempts to numerically integrate this orbit. Runs with various inclinations showed a variety of chaotic behaviors resulting from the frequent close encounters with the inner planets. Dependence of the frequency of encounters on the orbital inclination relative to the inner planets was observed. Encounters usually but not always disrupted the 3:1 mean motion resonance with Jupiter. A test using the orbital elements of Toutatis but an eccentricity of 0.0 showed periodic behavior with the eccentricity increasing to 0.12 in a period of 10,000 years.


If this report amounts to anything, I credit my supervisor Arthur Whipple, then member of the research faculty of the University of Texas Astronomy Department. He suggested the topic and provided the integration codes, guidance, and inspiration. I also thank my parents and my then fiancee--now my wife--for their support.

Investigation of evolution of orbits similar to that of (4179) Toutatis:

Link to updated information on Toutatis and asteroids near the 3:1 resonance with Jupiter (as of 28 June 2003).

© 1994-2003, 2008 by Wm. Robert Johnston.
Last modified 2 November 2008.
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