Exoplanet Discovery: Rare Earth Metal Found on Galaxy's Hottest World.
Astronomers have detected the rare earth metal terbium in the atmosphere of KELT-9b, a hot Jupiter exoplanet located 670 light-years away. This is the first time terbium has been found on a distant world, and its presence suggests that KELT-9b and its host star formed from materials that included ejecta from violent events such as supernova explosions or collisions between neutron stars. The discovery of heavy elements in exoplanet atmospheres helps scientists determine their age and how they were formed, and could lead to the discovery of Earth 2.0 in the future.