Dwarf planet Eris, similar in size to its better-known cosmic cousin Pluto, has remained an enigma since being discovered in 2005 lurking in the solar system's far reaches. While Pluto was explored by NASA's New Horizons spacecraft during a 2015 flyby, Eris - about 40% further from the sun - has never been visited.
But scientists are gaining a fuller understanding of Eris and its differences with Pluto thanks to research that discerns details about this frigid remote world's internal structure and composition based on its orbital relationship with its moon Dysnomia.
Eris, the researchers said on Wednesday, appears to have a rocky interior below a shell of ice. Pluto also has an icy exterior with rock below, but possesses a higher ice content and is thought to harbor an underground liquid ocean.
