Dynamical Spreading of Asteroid Families by the Yarkovsky Effect
William F. Bottke et al. (2001)
- Published
- Nov 23, 2001
- Journal
- Science · Vol. 294 · No. 5547
- DOI
- 10.1126/science.1066760
At a GlanceAI
Yarkovsky-driven drift plus resonances explain asteroid family spreading, sharp Kirkwood-gap edges, and odd family “fugitives.”
SummaryAI
This paper argues that the wide present-day orbital spread of many asteroid families cannot be interpreted as purely collision-ejection velocities, because small family members have since drifted in semimajor axis via the Yarkovsky thermal force. Using the Koronis family as a case study, the authors show that size-dependent Yarkovsky drift naturally produces the observed size sorting and, when combined with secular and mean-motion resonances, generates asymmetric family shapes and sharp truncations at nearby Kirkwood gaps. Resonance interactions can also move some fragments onto short-lived planet-crossing trajectories, explaining why long-lived families can still supply objects found near strong resonances or even among near-Earth asteroids. The implication is that family orbital structure records billions of years of thermal-dynamical evolution, so inferring the original breakup physics from today’s (a,e,i) dispersion—especially for D≲20 km—can be misleading without modeling Yarkovsky and resonances.
Method SnapshotAI
Long-timescale numerical orbit integrations of synthetic family fragments including Yarkovsky thermal forces and resonance dynamics, compared against observed proper-element distributions.
BackgroundAI
Basics of asteroid families and proper orbital elements, plus familiarity with Yarkovsky drift and orbital resonances in solar system dynamics.
A nice paper!
— ES