By Jonathan O’Callaghan
Historic Collection / Alamy Stoc
An object on the outer edges of the solar system may have a large moon orbiting it at an unusually close distance. The find could help explain how such binary objects evolved.
José-Luis Ortiz from the Institute of Astrophysics of Andalusia in Spain and his colleagues observed the previously discovered object, known as 2002 TC302, in January 2018 when it eclipsed a distant star, casting a shadow on Earth and allowing its properties to be studied.
From 12 separate observations, the team deduced that …
