Project P6: Collision properties of solids at low to moderate impact velocities (IGeP/Braunschweig)


It was recently discovered that planetesimals may form through the gentle gravitational collapse of clouds of mm-sized dust aggregates (“pebbles”). Based on this, we will thus investigate in project P6 the collision behavior and optical properties of pebble-pile bodies in debris disks. We will perform laboratory experiments for collision velocities between 1 m/s and 1,000 m/s, on which we will base an empirical collision model. This model will then be calibrated with empirical data of observed cliff collapses on comet 67P/Churyumov-Gerasimenko. Moreover, we will estimate the optical properties of the near-surface material of 67P/Churyumov-Gerasimenko for sub-mm/mm wavelengths by comparison between thermophysical model calculations of the temperature stratification and observations by the Rosetta/Miro instrument. Project P6 will provide the derived collision model to projects P1−P3, the optical data of the comet material to project P4, and pebble-pile samples to project P5 with which joint spectroscopic measurements will be performed. Joint impact experiments in Braunschweig and Freiburg are foreseen with project P7.