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
Emanuel Swedenborg well as spirits from planets beyond the solar system. From the 'encounters', he concluded that the planets of our solar system are inhabited and that such an enormous undertaking as the universe could not have been created for just one race on a planet or one 'Heaven' derived from its properties per planet. Many Heavenly societies were also needed to increase the perfection of the angelic Heavens and Heaven to fill in deficiencies and gaps in other societies. He argued: "What would this be to God, Who is infinite, and to whom a thousand or tens of thousands of planets,