According to CFA, some theories imply that Pluto’s four other siblings Styx, Nix, Kerberos and Hydrawere also formed during the initial event and drifted away. However, simulations by CFA astronomer Scott Kenyon and a colleague demonstrated that Pluto and Charon possibly came into existence after particles amalgamated together in the disk around the sun, in the same way Earth was formed. A subsequent event left the bodies at their current sizes but kept them tied to each other by gravity as a binary pair.
The impact left a trail of debris that integrated in a circumbinary disk, the CFA astronomers add. With time, the four smaller siblings formed from accumulation of debris in the circumbinary disk. Pluto is a dwarf planet belonging to the Kuiper Belt, which comprises a group of bodies that revolve in a disk-like zone, according to NASA.