Hygeia

Hygiea (minor planet designation: 10 Hygiea) is a major asteroid located in the main asteroid belt. With a diameter of 434 kilometres (270 mi) and a mass estimated to be 3% of the total mass of the belt, it is the fourth-largest asteroid in the Solar System by both volume and mass. In some spectral classifications it is the largest of the dark C-type asteroids with a carbonaceous surface, in others it is second after 1 Ceres.

Observations taken with the Very Large Telescope's SPHERE imager in 2017 and 2018, and announced in late 2019, revealed that Hygiea is nearly spherical and is close to a hydrostatic equilibrium shape. The authors of the study therefore consider it a possible dwarf planet.Hygiea is conjectured to have been disrupted by an impact and the subsequent debris reaccumulating. The disruptive impact produced the largest known collisional family.