Gravoturbulent planetesimal formation

We present a new scenario for the rapid formation of planetesimals based on the combined effects of turbulence and gravity. While it was generally accepted that these two effects cancel each other out, we found their interaction to be extremely beneficial for the accumulation of larger objects bound by gravity. Meter-sized objects get concentrated by turbulence; these over-densities start to get enhanced even further due to a clumping instability and finally densities are large enough that heaps of boulders fit into their combined Roche Lobe. At the same time, the residual velocity is low enough to allow for further collapse. Typical object masses that result in our numerical simulations are in the order of the minor planet Ceres.