Planet Formation

Every planetary system forms in a thin disk of gas and dust orbiting a young star. Small dust grains, a micron or two in size, collide and merge into large aggregates that settle into the midplane of the disk. In the midplane, aggregates grow into planetesimals with diameters of roughly 1 km. Collisions between planetesimals produce planets. SSP scientists use theoretical calculations to understand how dust grains evolve and how planetesimals become planets.