Measurement of Cohesion in Asteroid Regolith Materials

Shober, Patrick
Harvey, Ralph
Kleinhenz, Julie
Carreno, Brandon
Waters, Deborah
Zeszut, Zoe
Gaier, James

Publication date

January 2017

Abstract

There is increasing evidence that a large fraction of asteroids, and even Phobos, have such low densities (<2 g/cu cm) that the are unlikely to be consolidated rocks in space.-Water is unlikely due to close orbits to the sun. Instead, many of these asteroids are thought to be made up of unconsolidated smaller particles of varying size referred to as rubble piles. Images of the asteroid Itokawa reinforce this hypothesis. What holds the rubble piles together? Gravitational forces alone are not strong enough to hold together rubble pile asteroids, at least not those that are rapidly spinning Van der Waals forces and or Electrostatic forces must therefore be responsible for holding them together. Previous work suggests that electrostatic forces...