Icarus http://doi.org/cs7v (2018)

It’s tempting to think of celestial bodies as shiny spheres gracing the sky. Alas, many asteroids don’t quite fit that romanticization. They often come as irregularly shaped rocks. The larger of these are thought to have been beaten into shape mainly by collisions, but smaller asteroids may also owe their form to earlier break-ups due to rapid spinning. To better understand the effect of rotationally induced failure, Masatoshi Hirabayashi and Daniel Scheeres numerically studied the deformation modes of 24 well-documented asteroids of less than 40 km in diameter.

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The spin state of small astronomical bodies can change as a consequence of long-term exposure to solar radiation pressure. And once the rotational speed exceeds a critical value, the body fails. In their finite-element analysis, Hirabayashi and Scheeres showed that the spin at which this happens and the region where the structure fails depends strongly on the original shape of the asteroid.