Experiments under microgravity on ReboundIng and Charged Asteroid regolith (ERICA)

abstract

The surface of small rubble pile asteroids often shows regions which are dominated by different grain sizes. There are bare rocky regions contrasting pond or sea like granular beds of small grains. There are often more ponds of small grains at different locations spread across the surface and the small grains do not necessarily all gather at the global gravitational minimum. Several mechanisms have been discussed for shaping these surfaces, inculding charging by UV radiation or solar wind, erosion, the so called brazil nut effect and a recetly suggested hypothesis called ballistic sorting. In this project we aim test a number of these hypothesis and therefor develop a special experiment inset for drop tower capsules that allows to perform experiments under realistic asteroid conditions. Especially the low gravity typically found on such bodies will be recreated with high precision in a steadily accerlaterted experiment volume which sits inside the weightless droptower capsule. In contrast to using a centrifuge we employ a linar accelerator to avoid distrubing the experiment by coriolis forces.

• T. Bogdan, J.E. Kollmer, J. Teiser, M. Kruss, G. Wurm, " LABORATORY IMPACT SPLASH EXPERIMENTS TO SIMULATE ASTEROID SURFACES", submitted 2019

experiment year: 2020
number of catapult launches: 18