Interpretations of family size distributions: The Datura example

Abstract

Young asteroid families are unique sources of information about fragmentation physics and the structure of their parent bodies, since their physical properties have not changed much since their birth. Families have different properties such as age, size, taxonomy, collision severity and others, and understanding the effect of those properties on our observations of the size-frequency distribution (SFD) of family fragments can give us important insights into the hypervelocity collision processes at scales we cannot achieve in our laboratories. Here we take as an example the very young Datura family, with a small 8-km parent body, and compare its size distribution to other families, with both large and small parent bodies, and created by both catastrophic and cratering formation events. We conclude that most likely explanation for the shallower size distribution compared to larger families is a more pronounced observational bias because of its small size. Its size distribution is perfectly normal when its parent body size is taken into account. We also discuss some other possibilities. In addition, we study another common feature: an offset or "bump" in the distribution occurring for a few of the larger elements. We hypothesize that it can be explained by a newly described regime of cratering, "spall cratering", which controls the majority of impact craters on the surface of small asteroids like Datura.

arXiv commentaccepted for publication in Icarus; 21 pages, 10 figures

References in corpus (13)

• Catastrophic disruptions revisited
• The Size Distributions of Asteroid Families in the SDSS Moving Object Catalog 4
• The Yarkovsky and YORP Effects
• Identification and Dynamical Properties of Asteroid Families
• Asteroid family ages
• Asteroid family identification using the Hierarchical Clustering Method and WISE/NEOWISE physical properties
• Constraining the cometary flux through the asteroid belt during the late heavy bombardment
• SPH calculations of asteroid disruptions: The role of pressure dependent failure models
• Asteroid Systems: Binaries, Triples, and Pairs
• A multi-domain approach to asteroid families identification
• Effect of rotational disruption on the size-frequency distribution of the Main Belt asteroid population
• Constraints on the original ejection velocity fields of asteroid families
• Detection of the YORP Effect for Small Asteroids in the Karin Cluster

Cited by in corpus (5)

• Asteroid Families: properties, recent advances and future opportunities
• Small Solar System Bodies as granular media
• Dynamically correlated minor bodies in the outer Solar system
• The Flux Distribution and Sky Density of 25th Magnitude Main Belt Asteroids
• Main Belt Asteroid Histories: Simulations of erosion, cratering, catastrophic dispersions, spins, binaries and tumblers