The 2015 discovery of the TRAPPIST-1 system, with its seven Earth-sized planets, has redirected much of the exoplanet search toward M-dwarf systems — and justifiably so. Based on Kepler data, researchers estimate M-dwarfs (the most common type of star) host around 10 billion Earth-sized planets in the Milky Way alone. But one question that immediately pops up regarding the search for exoplanets is that of habitability. In addition to other criteria, the presence of an atmosphere is crucial f