An element spotted in an exoplanet is the heaviest element yet to be identified in a world beyond our solar system. Elements like this are expected to be both relatively rare and difficult to spot, but finding them is key to understanding how planets form and evolve over time.
Wei Wang at the National Astronomical Observatories of China and his colleagues found this heavy element, samarium, in a planet called MASCARA-4b, which is about 557 light years from Earth. MASCARA-4b is an ultra-hot Jupiter, which…