what is a rocky 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.ercury in the Solar System has a metallic core equal to 60â70% of its planetary mass. Iron planets are believed to form in the high-temperature regions close to a star, like Mercury, and if the protoplanetary disk is rich in iron. Coreless planet.