The Potato Radius: a Lower Minimum Size for Dwarf Planets
Abstract
Gravitational and electronic forces produce a correlation between the mass and shape of objects in the universe. For example, at an average radius of ~ 200 km - 300 km, the icy moons and rocky asteroids of our Solar System transition from a rounded potato shape to a sphere. We derive this potato-to-sphere transition radius -- or "potato radius" -- from first principles. Using the empirical potato radii of asteroids and icy moons, we derive a constraint on the yield strength of these bodies during their formative years when their shapes were determined. Our proposed ~ 200 km potato radius for icy moons would substantially increase the number of trans-Neptunian objects classified as dwarf planets.
- Publication:
-
arXiv e-prints
- Pub Date:
- April 2010
- DOI:
- 10.48550/arXiv.1004.1091
- arXiv:
- arXiv:1004.1091
- Bibcode:
- 2010arXiv1004.1091L
- Keywords:
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- Astrophysics - Earth and Planetary Astrophysics;
- Physics - Geophysics
- E-Print:
- 11 pages, 3 figures, in press, 2010, Australian Space Science Conference Series: Proceedings of the 9th Australian Space Science Conference, eds W. Short &