The Yarkovsky effect is not responsible for small crater depletion on Eros and Itokawa

✍ Scribed by David P. O’Brien

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 568 KB
• Volume: 203
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1016/j.icarus.2009.03.038

✦ Synopsis

The near-Earth Asteroids Eros and Itokawa show a pronounced lack of small ([100 m) craters, the vast majority of which were formed during their time in the main belt, and this has been cited as possible evidence that small ([10 m) impactors are efficiently removed from the main belt by the Yarkovsky effect. Using well-tested models for the evolution of the main-belt size distribution and the evolution of crater populations on asteroid surfaces, I show that a pronounced lack of small impactors would require sizedependent removal far stronger than can result from the Yarkovsky effect (or any other known process). Furthermore, such strong removal would lead to wavelike perturbations in the main-belt and near-Earth asteroid size distributions that are inconsistent with their observed size distributions, as well as the cratering records on asteroid surfaces. A more likely explanation is that processes on asteroid surfaces, such as seismic shaking, are responsible for erasing small craters after they form.