The Extreme-UV Radiation Environment of Extrasolar Planets: the ESCAPE Small Explorer Mission

The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) photon and high-energy particle fluxes from the host star. The EUV flux also drives the demographics of the short-period planet population and regulates the ability for rocky planets to maintain habitable environments long enough for the emergence of life. In this talk, I will present the Extreme-ultraviolet Stellar Characterization for Atmospheric Physics and Evolution (ESCAPE) mission, an astrophysics Small Explorer mission to be submitted to the upcoming Astrophysics Small Explorer call. ESCAPE employs extreme- and far-ultraviolet spectroscopy (80 - 1650 Angstroms) to characterize the high-energy radiation environment in the habitable zones around nearby stars. ESCAPE provides the first comprehensive study of the stellar EUV and stellar coronal mass ejection (CME) environments that control atmospheric mass-loss and determine the habitability of rocky exoplanets. ESCAPE will survey over 200 stars, including known planet hosts, to measure EUV irradiance, EUV flare rates, and the properties of CMEs. The ESCAPE instrument comprises a grazing incidence telescope feeding multiple diffraction gratings and a photon-counting detector. The science instrument will be assembled and tested in the space hardware facilities at the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics. Data archives will reside at the Mikulski Archive for Space Telescopes (MAST).