When extrasolar planets are observed to transit their parent stars, we are granted unprecedented access to their physical properties. It is only for these systems that we are permitted direct estimates of the planetary masses and radii, which in turn provide fundamental constraints on models of their physical structure. Furthermore, such planets afford the opportunity to study their atmospheres without the need to spatially isolate the light from the planet from that of the star. Recently, astronomers have taken a first glimpse into the atmospheric chemistry and dynamics of these puzzling worlds. I will review the most recent results, and then describe a new observatory that will survey 2000 nearby M-dwarfs with a sensitivity to detect rocky planets orbiting within their stellar habitable zones.

Refreshments will be available in the Steward Lobby at 3:30pm.