Formation and evolution of the Solar System through further collisions, growing at the rate of centimetres per year over the course of the next few million years. The inner Solar System, the region of the Solar System inside 4 AU, was too warm for volatile molecules like water and methane to condense, so the planetesimals that formed there could only form from compounds with high melting points, such as metals (like iron, nickel, and aluminium) and rocky silicates. These rocky bodies would become the terrestrial planets (Mercury, Venus, Earth, and Mars). These compounds are quite rare in the Universe, comprising only 0.6% of the mass of the
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