Dr. Steinn Sigurdsson
Penn State

University of Florida Astronomy Colloquium - Sept. 17, 2008

Exotic Earths

Planets have been found in extreme systems; we have found planets where detection techniques have the requisite sensitivity. New theoretical modeling suggests that habitable terrestrial planets may be found in many of the already known "hot Jovian" systems of giant planets orbiting close to their host stars. In our models, protoplanetary cores survive the migration phase, in which the giant planets move from the outer orbits in which they form, to the warm inner system, with the terrestrial planetary embryos re-assembling into water rich terrestrial planets in the habitable zone, outside the orbit of the giant planets, quite unlike the solar system.

Earths are likely to be common, not rare, and we should anticipate a very wide range of possible planetary systems and sites for life to start and evolve.