Outer Planets

Infrared spectra of icy satellites contain information about the surface composition and the phase state of those materials.  For example, the phase of H2O-ice can be used to interpret the temperature and radiation history of an icy surface.  Optical constants derived from laboratory data are needed to create model spectra for comparison to observations and may lead to a new understanding of surface processes.

We simulate the formation of planetary systems around Alpha Centauri B. The N-body accretionary evolution of a 1/r disk populated with 400-900 lunar-mass oligarchs is followed for 200 Myr. All simulations lead to the formation of multiple-planet systems with at least one planet in the 1-2 Msun mass range at 0.5-1.5 AU. We examine the detectability of our simulated planetary systems by generating synthetic radial velocity observations including noise based on the radial velocity residuals to the recently published three planet fit to the nearby K0V star HD 69830.

There are at least 37 objects in this solar system with masses greater than 1020 kg, two thirds of which have surfaces made primarily of water ice. The handful of icy bodies studied by spacecraft have revealed an enormous diversity of bizarre and unanticipated features, from geysers on Triton and Enceladus, to the peculiar shapes of Iapetus and 2003 EL61. I will discuss three aspects of icy body geodynamics: using surface observations to constrain their thermal evolution; the role of tidal heating; and their potential to undergo reorientation. 

Spectroscopy, particularly in the near-infrared, continues to be the most effective means for determining the compositions of the surfaces of planetary bodies. Planetary spectroscopy has moved beyond the mere identification of species to the quantitative interpretation of mixtures of several materials and the physical states in which they occur. Dr.