Planetary rings, like those of Saturn, are made up of countless particles ranging in size from micron-sized dust up to miniature moons tens of meters across. These particles collide frequently, but at ...
Planetesimals are the building blocks of planets. Asteroids and comets are leftover planetesimals from the time of formation of our own solar system. The formation of km-sized or larger planetesimals remains ...
Asteroids, Comets, and Small Moons
Asteroids are the rocky leftovers from the formation of the solar system. The largest asteroid, Ceres, and a few others, are dwarf planets, but the overwhelming majority ...