High-velocity dust collisions: forming planetesimals in a fragmentation cascade with final accretion |
| |
Authors: | Jens Teiser Gerhard Wurm |
| |
Affiliation: | Institut für Planetologie, Wilhelm-Klemm-Str. 10, D-48149 Münster, Germany |
| |
Abstract: | In laboratory experiments we determine the mass gain and loss in central collisions between centimetre- to decimetre-size SiO2 dust targets and submillimetre- to centimetre-size SiO2 dust projectiles of varying mass, size, shape and at different collision velocities up to ∼56.5 m s−1. Dust projectiles much larger than 1 mm lead to a small amount of erosion of the target but decimetre targets do not break up. Collisions produce ejecta, which are smaller than the incoming projectile. Projectiles smaller than 1 mm are accreted by a target even at the highest collision velocities. This implies that net accretion of decimetre and larger bodies is possible. Independent of the original size of a considered projectile, after several collisions, all fragments will be of submillimetre size which might then be (re)accreted in the next collision with a larger body. The experimental data suggest that collisional growth through fragmentation and reaccretion is a viable mechanism to form planetesimals. |
| |
Keywords: | methods: laboratory planets and satellites: formation Solar system: formation planetary systems: formation planetary systems: protoplanetary discs |
|
|