Investigation of a Resonant Mechanism for Capture of Irregular Satellites

Planetary Science Institute, Tucson AZ

Investigators

Abstract

AST 0607777 Kortenkamp Drs. Kortenkamp and Tricarico will use this award to examine a resonant mechanism for capture of irregular satellites during planetary migration. The mechanism involves an unusual 1:1 coorbital resonance between the planet and object to be captured. The primary objective is to determine whether this resonant mechanism will enable giant planets to capture irregular satellites during the late stages of planetary migration. A secondary objective is to determine whether this resonant mechanism can help explain the capture of Phobos and Deimos by Mars. Throughout the proposed research, Kortenkamp and Tricarico will utilize computer intensive numerical simulations. These methods include direct N-body numerical integration and modified N-body integrations that incorporate algorithms to simulate effects such as planetary migration. Understanding the origin of irregular satellites is a long standing problem in planetary science. The merit of this objective is all the more timely considering the dozens of new irregular satellites recently discovered orbiting all four giant planets in the Solar System. Kortenkamp and Tricarico each have experience modeling Solar System dynamics using a variety of numerical techniques. The research will help constrain recent theories regarding the primordial orbital evolution of the giant planets. One consequence of these theories is that irregular satellites were likely captured at a much later time than previously believed and thus without assistance from primordial dissipative mediums vital to other capture mechanisms. Kortenkamp and Tricarico will apply a unique solution to this problem by exploring a new resonant mechanism for capture of irregular satellites during the late stages of planetary migration. Also, owing to the proximity of Mars to the asteroid belt, their secondary objective of studying capture of Phobos and Deimos may provide insight into the mechanisms responsible for excitation and depletion of the asteroid belt. Thus, while they will be studying the capture of irregular satellites, this work will have a much broader impact on general models of early solar system evolution. In addition to the intrinsic merit of the proposed research, the investigators see an important broader impact on their activities at the Planetary Science Institute. Kortenkamp has a history of working with the general public, amateur astronomers, and groups of students and teachers. He also recently served as scientific consultant for a series of grade K-3 childrens science books. Tricarico is the author of a free open-source graphical simulator widely used by amateur astronomers to study dynamics of minor planets. He is also developing a SETI@Home type distributed computing program for orbital dynamics problems. Tricarico is also involved in a collaboration to provide news programs with numerical computations and graphical animations related to significant astronomical events.