Flora family

The Flora or Florian family of asteroids is a large grouping of S-type asteroids in the inner main belt, whose origin and properties are relatively poorly understood at present. Roughly 4-5% of all main belt asteroids belong to this family.

Because of its poorly defined boundaries, and the location of Flora itself near the edge, this asteroid group has also sometimes been called the Ariadne(an) family, when Flora did not make it into the group during an analysis (e.g. the WAM analysis by Zappala 1995).

The Flora family of asteroids may be the source of the Chicxulub (Cretaceous–Paleogene) impactor, the likely culprit in the extinction of the dinosaurs.

Characteristics

The largest member is 8 Flora, which measures 140 km in diameter, and comprises about 80% of the total family mass. Nevertheless, the parent body was almost certainly disrupted by the impact/s that formed the family, and Flora is probably a gravitational aggregate of most of the pieces. 43 Ariadne makes up much of the remaining mass (about a further 9%), with the remaining family members being fairly small, below 30 km in diameter.