Strong Winds for Planetary Formation

The GDGSF is located at the Max Planck Institute for Dynamics and Self-Organization (MPIDS), in one of the laboratories belonging to the Turbulence subdivision of the department of Fluid Dynamics, Pattern Formation and Nanobiocomplexity
The GDGSF is located at the Max Planck Institute for Dynamics and Self-Organization (MPIDS), in one of the laboratories belonging to the Turbulence subdivision of the department of Fluid Dynamics, Pattern Formation and Nanobiocomplexity

by Holly Capelo

 

In our experiment in the Göttingen Dilute Gas Stream Facility GDGSF, we produce a 'wind' which contains very small spherical particles. The density of the wind is 1/100th the density of air at sea level.  The particles' sizes range from approximately 70 micrometres (the same as the thickness of a human hair) down to 20 micrometres (about half of the limit of what is visible to the unassisted human eye).  When the particles are trapped in the flow, we use high-resolution cameras to track their positions, to learn if and how the particles may swarm together in the flow and how the particles' group behaviour is different from the simple dynamics of individual particles. 

 

The spheres in the experiment are analogous to the small grains which are present in the dust- and gas- filled discs around young stars. In such environments, it is believed that particle-gas fluid instabilities, including the streaming instability, play a prominent role in the process of concentrating dust particles to assist in the formation of bigger objects like planetesimals, which are the precursors of planets.   

Editor's note:

An experimental simulation of collisions between dust aggregates in the early solar system to understand the first steps of planet fomation is beautifully portrayed by an article in the Journal of Visualized Experiments JoVE by

Blum, J., Beitz, E., Bukhari, M., Gundlach, B., Hagemann, J. H., Heißelmann, D., et al. Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System. J. Vis. Exp. (88), e51541, doi:10.3791/51541 (2014).

http://www.jove.com/video/51541/laboratory-drop-towers-for-experimental-simulation-dust-aggregate