How Pluto captured its largest moon: a new theory

Pluto might have hogged much of the spotlight historically, but the dwarf planet is actually part of a double act, alongside its biggest satellite, Charon. A new analysis suggests that Pluto used its gravity to entice Charon into this pas de deux, hugging the smaller body close before the two split into a whirling pair — a mechanism dubbed ‘kiss-and-capture’. Previously, scientists thought that the binary system formed as the result of a collision between two proto-bodies, with much of proto-Charon’s material sloshing over to proto-Pluto. The new idea suggests that Charon kept much of its core and mantle.