The moon was named Dysnomia ( from the Ancient Greek word that means `` lawlessness '' ) after the daughter of the Greek goddess Eris . It was discovered in 2005 by Mike Brown and the laser guide star adaptive optics team at the W. M. Keck Observatory , and carried the provisional designation of ' until officially named Dysnomia ( from the Ancient Greek word meaning `` lawlessness '' ) after the daughter of the Greek goddess Eris .