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.
Keywords
Cite
@article{arxiv.1004.1091,
title = {The Potato Radius: a Lower Minimum Size for Dwarf Planets},
author = {Charles H. Lineweaver and Marc Norman},
journal= {arXiv preprint arXiv:1004.1091},
year = {2010}
}
Comments
11 pages, 3 figures, in press, 2010, Australian Space Science Conference Series: Proceedings of the 9th Australian Space Science Conference, eds W. Short & I. Cairns, National Space Society of Australia