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 for life as we know it to exist.
One direct way to measure potential exoplanet habitability is to estimate the fierceness of a host star’s stellar winds, and then determine how well the surrounding planets’ can retain their atmospheres against these winds. And this is exactly what the authors of a study published in the Proceedings of the National Academy of Sciences have done.
