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 Solar System in fiction The Solar System and its various bodies (planets, asteroids, moons, etc.) were the earliest objects to be treated as fictional locations in works of science fiction. Among these, imaginary voyages to and explorations of Earth's Moon are found in seventeenth century literature. By the early twentieth century, following the increase in scientific and technological development spurred by the Industrial Revolution, fictional journeys to (or from) the Solar System's other planets had become common in fiction. Early literature regarding the Solar System, following scientific speculations dating back to the 17th century, assumed that every planet hosted its