The Solar System contains planets
Solar System . is the gravitationally bound system comprising the Sun and the objects that orbit it , either directly or indirectly.The natural satellites ( moons ) orbiting the Solar System 's planets are an example of the latter . Of those objects that orbit the Sun directly , the largest eight are the planets , Historically , several other bodies were once considered planets , including , from its discovery in 1930 until 2006 , Pluto . The four smaller inner planets , Mercury , Venus , Earth and Mars , are terrestrial planets , being primarily composed of rock and metal .