Astrophysics Colloquium Into the Unknown: Exoplanet Characterization from Telescopes Past, Present, and Future Presented by Kevin Stevenson Space Telescope Science Institute Thursday, April 19, 2018 11:00 A.M. in 169-336 and on Webex Abstract Exoplanet characterization has made significant advances in the last decade and will continue to do so for the foreseeable future. From the early days of Spitzer and Hubble, to the pending launch of JWST and even future mission concepts still under consideration, revealing exoplanet atmospheres' climates, compositions, and thermal structures through the transit technique has arguably been the most prolific means to study worlds outside of our own system. I will discuss recent efforts to understand exoplanet atmospheres through a 660-hour Spitzer phase curve survey program that is targeting seven short-period extrasolar planets, a multi-cycle Spitzer program that is monitoring transit timing variations of a K2 system, and a preparatory HST program whose primary goal is to identify targets for the recently-approved transiting exoplanet community early release science program with JWST. I will conclude with an introduction to the Origins Space Telescope (one of four large mission concepts under consideration for the 2020 decadal survey) and a description of how OST can expand upon the legacy of missions past and present to study the climates of Earth-size worlds orbiting within the habitable zones of nearby M-dwarf stars. JPL Contact: Tiffany Kataria (3-4935)   Site Manager: Webmaster: CL 08-3220