Pluto’s moons
Why does Pluto, such a small world, have so many moons?
A giant impact likely made Charon and left a debris disc that became Styx, Nix, Kerberos and Hydra. Charon is half Pluto’s width, so the two of them are a double world — and the four small moons sit in the gravity of the pair, not of a single point. See them on Pluto and its moons.
One smash, five moons
Charon is so big that the point Pluto and Charon both orbit sits outside Pluto’s surface. No other named pair in the solar system does that. The four small moons — Styx, Nix, Kerberos, Hydra — go round the pair on tidy, nearly circular paths, which is what you expect from leftover debris after an impact, not from random captures.
Small does not mean moonless. It means the moons, if they exist, probably share one origin story rather than a billion years of capture.
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The little four tumble
Styx, Nix, Kerberos and Hydra do not keep one face to Pluto. They sit in the gravity of a rotating pair rather than a single point, so their day lengths change in a way that looks random from month to month. New Horizons watched that tumble on one afternoon in 2015. Nobody has been back.