The Diverse Population of Small Bodies of the Solar System

Small bodies are rocky and/or icy objects, usually ranging in size from a few meters to a few hundreds of kilometers. They comprise near-Earth and main-belt asteroids, Jupiter Trojans, trans-Neptunian objects, Centaurs, comets, and a recently discovered category called the transitional objects. Their physical nature, distribution, formation, and evolution are fundamental to understand how the solar system formed and evolved and, ultimately, how planetary systems are formed in other stars. The number of discoveries regarding exoplanets and debris disks is continuously increasing, and therefore it is crucial to first understand our own solar system’s provenance and evolution in order to better interpret what is going on in newly discovered planetary systems. In this chapter, the main physical and compositional properties of the different populations of small bodies of the solar system are reviewed.