The search for life around other stars is essentially a search for a habitable zone – the area around a star where the distance is warm enough to sustain liquid water on the surface, but cold enough such that the water does not boil away or escape.
This definition of habitable zone now has to change to take into account the star itself. New research shows that winds coming off Red Giant stars can strip the planet of Oxygen. No Oxygen, no life. This means that our nearest confirmed Earth-sized exoplanet, around Proxima Centauri and only 4 light-years away, is not a good spot to go look for neighbors.
“If we want to find an exoplanet that can develop and sustain life, we must figure out which stars make the best parents,” said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA’s Goddard Space Flight Center. “We’re coming closer to understanding what kind of parent stars we need.”