Yes, Eris has at least one moon, which is named Dysnomia. This moon was discovered in 2005 and is named after the daughter of Eris, the goddess of discord in Greek mythology.
Dysnomia is relatively small, with its diameter estimated to be around 700 kilometers (about 430 miles). The discovery of Dysnomia was significant as it helped astronomers calculate the mass of Eris more accurately, which is crucial for understanding the characteristics of this distant dwarf planet.
In summary, while Eris is known primarily for being one of the largest known dwarf planets in the solar system, its moon Dysnomia adds an interesting aspect to its study and provides additional insight into the dynamics of celestial bodies far beyond our own planet.