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
The Web Planet to land on an unknown planet. Whilst exploring with Ian, the Doctor recognises the planet as Vortis; however, the presence of several moons in the sky of the normally moonless planet puzzles him. Inside the ship an unknown force acting through Barbara's gold bracelet draws her outside, leaving Vicki alone. The TARDIS is then pulled by an unseen force across the planet's surface. In her trance, Barbara walks into a trio of the butterfly-like Menoptra. They remove her bracelet, freeing her of the trance, then debate what to do with her. She escapes, but the Zarbi immediately capture her. Brainwashed