Nearby 2.3-Earth-Mass World in Habitable Zone Sparks Habitability Hopes

Astronomers refined the mass of the nearby exoplanet GJ 3378b to about 2.3 Earth masses, placing it in the rocky super-Earth category inside its red dwarf's habitable zone at roughly 25 light-years away. While this makes it one of the closest likely Earth-like worlds, whether it has an atmosphere remains unknown; without one, liquid surface water is unlikely. It is a prime target for future biosignature searches as scientists seek to determine if we are alone.