Flora family

The Flora family of asteroids is a big group of S-type asteroids in the closer part of the main belt, whose origin and properties are not well understood right now. About 4-5% of all main belt asteroids belong to this family.

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

Characteristics

The biggest member is 8 Flora, which mesures 140 km in diameter, and takes up about 80% of the total family mass. Nevertheless, the parent body was almost for sure destroyed by the impact/s that made the family, and Flora is probably a gravitational aggregate of most of the pieces.^[source?] 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.

Unrelated asteroids

Because of the high background density of asteroids in this part of space, one might expect that a great number of asteroids unrelated to the collision that made the family would be present. However, few have been found. This is because unrelated asteroids are hard to distinguish from family members because the family is of the same spectral type (S) that dominates the closer main belt overall. The few unrelated asteroids that have been found are all small (Florczak et al. 1998, and also by inspection of the PDS asteroid taxonomy data set Archived 2003-11-19 at Archive.today for non S-type members.) They include 298 Baptistina, 422 Berolina, 2093 Genichesk, 2259 Sofievka (the biggest, with a 21 km diameter), 2952 Liliputia, 3533 Toyota, 3850 Peltier, 3875 Staehle, 4278 Harvey, 4396 Gressmann, and 4750 Mukai.

References

V. Zappalà, Ph. Bendjoya, A. Cellino, P. Farinella and C. Froeschlé, Asteroid Families: Search of a 12,487-Asteroid Sample Using Two Different Clustering Techniques Archived 2020-03-28 at the Wayback Machine, Icarus, Volume 116, Issue 2 (August 1995), pages 291-314
M. Florczak et al. A Visible Spectroscopic Survey of the Flora Clan, Icarus Vol. 133, p. 233 (1998).
PDS asteroid taxonomy data set Archived 2003-11-19 at Archive.today
S.J. Bus and R.P. Binzel, Phase II of the Small Main-Belt Asteroid Spectroscopic Survey, Icarus Vol. 158, p. 106 (2002). Data set online here Archived 2006-01-05 at the Wayback Machine.
D. Nesvorný et al. The Flora Family: A Case of the Dynamically Dispersed Collisional Swarm?, Icarus, Vol. 157, p. 155 (2002).
AstDys site. Proper elements for 96944 numbered minor planets.
P. Tanga et al. On the Size Distribution of Asteroid Families: The Role of Geometry, Icarus, Vol. 141, p. 65 (1999).
J. Veverka et al. Galileo's Encounter with 951 Gaspra: Overview, Icarus, Vol. 107, p. 2 (1994).