Terrestrial planet Terrestrial planet A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth ("Terra" and "Tellus"), as these planets are, in terms of structure, "Earth-like". Terrestrial planets have a solid planetary surface, making them substantially different from the larger giant planets, which are composed mostly of some combination of hydrogen, helium, and water existing in various
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