All throughout the Universe, there are normally three ways that moons can form.
Pluto, shown as imaged with Hubble in a composite mosaic, along with its five moons. Charon, its largest, must be imaged with Pluto in an entirely different filter due to their brightnesses. The four smaller moons orbit this binary system with a factor of 1,000 greater exposure time in order to bring them out. Nix and Hydra were discovered in 2005, with Kerberos discovered in 2011 and Styx in 2012. These five moons were likely formed via an early collision, rather than either in situ or as a result of gravitational capture. (Credit: NASA, ESA, and M. Showalter (SETI Institute))