SIR Earth and Space Science Investigation Abstract
CRASH!!!! ORBITAL INSTABILITY OF ASTEROID 21238 AND THE CHAOS/RESONANCES IN THE SURROUNDING NEIGHBORHOOD
Presenters:
Grant L. Barbosa, Illinois Mathematics and Science Academy
Emily J. Breckenfelder, Illinois Mathematics and Science Academy
Advisors:
Dr. Geza Gyuk, Adler Planetarium
Dr. Mark Hammergren, Adler Planetarium
Abstract:
Asteroid 21238 has a rare spectrum identifying it as a basaltic asteroid. Magna and Vesta were the only two confirmed independent basaltic asteroids. The location of 21238 in the outer main belt suggests that it developed independently of Vesta. The asteroid belt is filled with resonances, which can change the orbital paths of asteroids. Therefore it is possible that the two asteroids were connected at some point in the past.
Using the SWIFT program, a long-term integration of the orbit was conducted. By integrating the orbit, the results allow investigating into the plausibility of the orbit of asteroid 21238 being drastically altered. The initial integration shows that the asteroid is stable for over two billion years, but if a resonance were to be close to asteroid 21238, confidence in the orbital stability would be substantially less.
A second type of integration was run to address this issue. A large number of test particles represented asteroids with varying eccentricities and semi-major axes. The results from these integrations revealed a bevy of resonances, however none were close enough to asteroid 21238 to likely alter its orbit.
Although it seems that asteroid 21238 is stable, neither integrations took into account the Yarkosky Effect. The Yarkosky Effect slowly perturbs the orbital path of asteroids. This effect could influence the orbit over the long term although the effect seems minimal in the short term. Beyond this, resonances could alter the orbit in unforeseen ways. Future integrations will take into account the effect of Yarkosky and resonances.