1. DAVID KIRSH RALPH PUDRITZ IAU 276 TORINO 2010 Planetesimal Formation in Turbulent Circumstellar Disks

2. Planetesimal Formation Planetesimals can’t grow from dust to protoplanet simply by snowballing through the disk  Fall into the central star  Fragment rather than stick Rocks and dust can be gathered in turbulent clumps in the disk gas If enough are gathered, they can collapse under their own gravity to create large planetesimals Johansen, A., Oishi, J. S., Mac Low, M.-M., Klahr, H., Henning, T., & Youdin, A. 2007a, Nature, 448, 1022

3. Simulation FLASH adaptive mesh refinement code with active particles Global simulations of the inner disk, torus of particles embedded

4. Particle settling First stage is the settling of particles down to the midplane

5. Particles differentiate