Solar System all have impact craters and tectonic surface features, such as rift valleys and volcanoes. The term "inner planet" should not be confused with "inferior planet", which designates those planets that are closer to the Sun than Earth is (i.e. Mercury and Venus). Asteroids except for the largest, Ceres, are classified as small Solar System bodies and are composed mainly of refractory rocky and metallic minerals, with some ice. They range from a few metres to hundreds of kilometres in size. Asteroids smaller than one meter are usually called meteoroids and micrometeoroids (grain-sized), depending on different, somewhat arbitrary definitions. The asteroid
Solar System in fiction and that Mars could hardly support any macroscopic life forms on its surface, much less an advanced civilization. In the 1980s it was shown that the surfaces of Jupiter's moons were just as hostile to life. More recent fiction focused on the Solar System has thus tended to address its exploration for purposes such as terraforming, the engineering of planets for human habitation, than the possibility of any existing life. The following works or series use multiple planets and other locations within the Solar System as their primary settings: Solar System in fiction The Solar System and its various bodies