Dr. Mark Showalter’s research focuses on the dynamics of rings and small moons in the Solar System. Dr. Showalter’s early work with Voyager data led to the discoveries of Jupiter's faint, outer "gossamer" rings and Saturn's tiny ring-moon, Pan.
In 2011, Dr. Showalter initiated a Hubble observing program focused on Pluto, which led to the discovery of two tiny moons. Their names, "Kerberos" and "Styx", were selected through an international naming campaign.