Ersa (moon)
Ersa is part of the Himalia group, a tight cluster of prograde irregular moons of Jupiter that follow similar orbits to Himalia at semi-major axes between 11-12 million km 6.8-7.5 million mi and inclinations between 26-31 . With an estimated diameter of 3 km 1.9 mi for an absolute magnitude ofr 15.9, it is one of the smallest known members of the Himalia group.