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
A Beautiful Planet star about half the size and mass of the Sun which lies in the direction of the constellation Cygnus, about 500 light-years away. The number "186" in the planet's name refers to the order in which its planetary system was discovered while scientists processed all of the data produced by the Kepler Space Telescope, and the planet itself is designated "f" because the first planet to be discovered in the system is designated as planet "b," the second discovered is "c," etc., and it was the fifth planet to be discovered. Even though the idea of interstellar travel to another