Haumea is one of the most peculiar objects in the outer Solar System. Its extreme rotation period — just under 4 hours — has deformed its shape into a triaxial ellipsoid, with the long axis ~2,322 km and the short axis about 1,026 km. Haumea has two known moons (Hi’iaka and Namaka), both believed to have formed from a giant impact that also set Haumea spinning and launched fragments that together form the “Haumean collisional family” of KBOs. In 2017, a stellar-occultation campaign revealed the first ring system known around any dwarf planet.