2006 Annual Science Report
University of Washington Reporting | JUL 2005 – JUN 2006
Delivery of Organic Materials to Planets
Quinn in collaboration with Lunine and Raymond have continued to study the accumulation of volatiles during the formation of the terrestrial planets. They have investigated the situation where the Giant planets undergo significant migration during the formation of the terrestrial planets, which implies a significantly different distribution of material in the initial Solar Nebula. They find that an initial distribution of material that falls off more quickly with distance from the star tends to produce terrestrial planets that are more numerous, more massive, closer to the star, have higher iron content, and have lower water content. However, the possibility of forming potentially habitable planets does not vary strongly with the initial radial distribution of the solid material.
Quinn, Raymond and Lunine have also investigated higher resolution simulations of the terrestrial planet formation and volatile delivery process. They find that the feeding zones of terrestrial planets slowly widen with time such that water rich material is not delivered until after several million years of evolution. Self scattering in the asteroid belt clears out more than 99% of the original mass, and stunts the growth of planetary embryos. Dynamical friction with large numbers of bodies plays a role in keeping the eccentricities of the forming terrestrial planets low. The delivery of water in these higher resolution simulations is less stochastic than has been previously thought.
With the SDSS (Sloan Digital Sky Survey) collaboration Quinn has been involved with the publication of a moving object catalog from the SDSS. Five color photometry of a large number of asteroids helps constrain the origin of asteroid families and asteroid chemical composition.