“Saturn's rings were left unfinished to show us how the world was made” .
How does our solar system fit among the great host of exoplanetary systems? It is not a typical sample of what is out there so it is not a good example of the “Principle of Mediocrity”. Its obvious advantage is that it is the only one that we can examine in detail and so forms the basis for current models of planetary origin. What is revealed are not only our eight planets, interesting though they are as possible analogs for exoplanets, but also hosts of other bodies in orbit either around the Sun or planets. We have over 160 satellites, four ring systems, dust, swarms of many different species of asteroids, KBOs, TNOs and wanderers such as comets, centaurs, NEAs and NEOs. The system resembles a half-finished long-abandoned building site, littered with leftover rubble and assorted debris. Although little of this detail is yet evident in exoplanetary systems, it is useful to examine our solar system in depth to see what actually happened in one disk around a star. It is not only a matter of just forming planets.
The solar system has long been a benchmark, becoming from familiarity, what was commonly expected to be a norm. But reality was different, as the first exoplanet discovery, Pegasi 51b, demonstrated so dramatically. Now even our system of planets is seen to be uncommon, the end result of chaotic and chance events.