Dust Aggregation
Dust particles in protoplanetary disks collide, stick together, and
grow in this way. Once aggregates have been formed, the result of
collisions will depend on material properties, and on the speeds of
collisions. The figure to the right, taken from Paszun & Dominik (A&A
507, 1023), shows the results of a detailed calculation of dust
aggregates, at different speeds. We see that at small speeds,
aggregates stick, at intermediate velocities, they compress each other
in central collisions, but they can also stretch each other by the
effect of inertia in glancing collisions. At still higher velocities,
destruction takes place and small grains are returned.
If you click on the 2D/3D Aggregation movies in the navigation bar, you can see these and other calculations animated into a video.