878 Mildred is a minor planet in the main belt orbiting the Sun. It is the lowest numbered, and thus the namesake, of the Mildred family of asteroids, a subgroup of the Nysa family. The Mildred subgroup, and by extension 878 Mildred itself, is thought to have been formed by a recent fragmentation event from a larger asteroid.
Read more about 878 Mildred: Discovery, Physical Properties