planetesimali
Planetesimali, or planetesimals, are solid bodies that form in protoplanetary disks around young stars and serve as the building blocks of planets. They typically range from kilometers to hundreds of kilometers in diameter and arise from the coagulation of dust and ice in the disk.
Formation occurs as microscopic grains collide and stick, growing from sub-micron particles to larger aggregates. Over
Planetesimali are essential to planet formation. Through successive collisions and mergers, they give rise to planetary
Evidence and observations come from multiple sources. Meteorites contain ancient clues about early planetesimal material, while
Composition of planetesimali varies with location in the disk; rocky, volatile-poor bodies form inside the snow