LPL Colloquium: Dr. Fred Ciesla
Planetesimal Collisions in the Early Solar System: What Can Meteorites Tell Us?
Dr. Fred Ciesla
Department of the Geophysical Sciences, U. of Chicago
Meteorites are largely derived from asteroids, leftover planetesimals that have been preserved over the history of the Solar System. As such, these samples have been used to infer the properties and early evolution of those bodies which accreted to form the planets. Since their formation, meteorite parent bodies have been subjected to heating by the decay of short-lived radionuclides and shock processing by high-velocity collisions which would have altered the original properties of the planetesimals and the materials they contain. To date, these effects have largely been studied independent of one another; however, planet formation models predict that thermal evolution of meteorite parent bodies coincided with the period of time when collision probabilities and velocities were highest among planetesimals. I will discuss how these early collisions affected the thermal evolution of meteorite parent bodies and what signatures of these events may be identified in meteoritic samples. I will also speculate as to how these signatures may be used to constrain the dynamic environment in which the terrestrial planets accreted.