Figure 9-7 RIVUXG Dwarf Planet Eris (a) Three perpendicular views of the orbit of Eris and Dysnomia compared to the planets and Pluto. Eris and Dysnomia’s orbit around the Sun ranges from 38 to 98 AU, and has an orbital eccentricity, e = 0.44, and an orbital inclination of 44°. (b) A Keck telescope image of dwarf planet Eris and its moon Dysnomia.