Astronomers today announced one of the most exciting exoplanet discoveries yet: an Earth-mass rocky world orbiting the nearest star to the Sun, Proxima Centauri. There had been hints before of such a world, but nothing was confirmed, until now. The planet, called Proxima b, is not only just slightly more massive than Earth, it orbits within the star’s “habitable zone.” The estimated temperatures of the planet could allow liquid water to exist on its surface. Not only is this planet potentially habitable, depending on other factors, it is also now the closest known exoplanet.
Read MorePale Red Dot: Astronomers discover potentially habitable exoplanet orbiting nearest star