Detecting and characterizing giant planets beyond Hubble

The current cohort of nearly 100 companions to Sun-like stars, in the Jovian-mass range, is beginning to suggest some planetary systematics whose investigation will be the task of future ground-based and space-based telescopes. We are beginning to understand, from Doppler surveys, the fraction of stars that have giant planets. In the case of one such planet, thanks to the ground-based observation of its transits, the mass and radius - hence the density - are well determined. Transits observed from Hubble Space Telescope provide some constraint on composition and upper atmospheric processes. While the most promising wavelength range for detailed atmospheric studies of extrasolar giant planets is the infrared, there are key features in the optical spectra that are of interest in studies of warmer giant planets.