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
Akaa Solar System Scale Model man-made spacecraft) and the concrete pillar representing its location is at the center of the neighbouring town Viiala, approximately 7 km away from the Sun. The speed of light in the scale model is exactly 10 cm/second, so walking the 50-meter distance from the Earth to Sun "at light speed" takes 8 minutes and 20 seconds. In 2018 scale model of Proxima Centauri -star was added to Akaa Solar System Scale Model. Proxima Centauri is a red dwarf star and the nearest star to our Solar System. It is located 4.24 light-years away and in the model's scale it has