The “demoted” dwarf planet Pluto and its largest moon Charon make an unusual pair, and for decades, scientists have been discussing how the binary system—in which each mutually orbits the other—came to be.

Scientists propose Pluto and its moon Charon formed through a "kiss and capture" event 4.5 billion years ago, challenging previous theories about their unique size ratio and orbital relationship.

Simulations suggest Pluto and its largest moon may have gently stuck together for a few hours before Charon settled into a stable orbit around the dwarf planet