Classification of Objects in the Solar System

Hanslmeier, Water in the Universe, Astrophysics and Space Science Library 368, DOl 10.1007/978-90-481-9984-6 3, Springer Science+Business Media B.V. 2011 

Asteroids, comets and smaller particles are also grouped into SSSBs, small solar system bodies. All categories of objects described above appear at specific locations in the solar system. The inner solar system contains the terrestrial planets and the Main Belt of asteroids. In the middle region there are the giant planets with their satellites and the centaurs. The outer solar system comprises the Trans-Neptunian objects including the Kuiper Belt, the Oort cloud, and the vast region in between. 

The solar system is not unique in the universe, in the beginning of 2010 about 400 extrasolar planetary systems were known. The formation of such systems seems to be a normal process. 

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