Dust Evolution in Protoplanetary Disks

Understand

(abridged) In the core accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals.

• Although dust grains are thought to grow from the submicron sizes typical of interstellar dust to micron size particles in the dense regions of molecular clouds and cores, the growth from micron size particles to pebbles and kilometre size bodies must occur in protoplanetary disks.
• This step in the formation of planetary systems is the last stage of solids evolution that can be observed directly in young extrasolar systems.
• In this chapter we review the constraints on the physics of grain-grain collisions as they have emerged from laboratory experiments and numerical computations.