Evolution of Exoplanet Atmospheres and their Characterisation

Project Coordinator/Proposer: Helmut Lammer
Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, A-8042, Graz, Austria
E-mail: helmut.lammer@oeaw.ac.at; Phone: 0043 316 4120 641; Fax: 0043 316 4120 690

Abstract: Recent studies and observations (with the Hubble and Spitzer Space Telescope) of transiting giant exoplanets suggest that spectra of transiting planets can be used to infer many properties of their atmospheres and internal structures, including hydrodynamic escape, hydrogen ENA clouds, thermal profiles, density, composition and evolution. The spectrum of the Earth displays features, such as O3, O2 and CH4 bands, or vegetation reflection, that are directly or indirectly inherited from the biosphere. To improve our understanding of the formation and evolution processes for the planets in our solar system and beyond, we propose a broad interdisciplinary investigation focused on planetary atmospheres. Our study will start from the origins of planets within the protoplanetary nebula and will follow their evolution due to thermal and non-thermal atmospheric escape processes -related to the host stars activity-, anorganic (e.g. fractionation due to loss processes, chemical changes due to energetic particles, etc.) and organic (life appearance) modifications, and finally will evaluate the impact of these processes on the planetary spectra. The results provided by this project will have important implications for present and future space missions, to detect and characterize exoplanets, like CoRoT, Kepler and further into the future Darwin/TPF. Thanks to those missions, comparative exo-planetology and the remote detection of life on extrasolar worlds will become a reality.