With a diameter of about 1,215 km, the France - sized moon is one of largest known objects in the Kuiper Belt, the region of icy,
rocky bodies beyond Neptune.
These
bodies, along with Pluto, are members of the Kuiper Belt, a population of
rocky potential comets orbiting
beyond Neptune.
Both objects formed among the
rocky and icy protoplanets
beyond the Solar System's «ice line» now located around 2.7 AUs, but the early development of Jupiter apparently prevented such large protoplanets between the gas giant and planet Mars from agglomerating into even bigger planetary
bodies, by sweeping many into pulverizing collisions as well as slinging them into the Sun or Oort Cloud, or even
beyond Sol's gravitational reach altogether.