what is meant by terrestrial
terrestrial. adjective. 1  Of or relating to the earth or its inhabitants. 2  Biology Living or growing on land or on or in the ground; not aquatic, arboreal, or epiphytic: terrestrial mammals; terrestrial apes; terrestrial orchids.3  Astronomy Similar to the planet earth in size or composition: terrestrial planets.4  Transmitted from structures on the earth and not ...djective. 1  Of or relating to the earth or its inhabitants. 2  Biology Living or growing on land or on or in the ground; not aquatic, arboreal, or epiphytic: terrestrial mammals; terrestrial apes; terrestrial orchids. 3  Astronomy Similar to the planet earth in size or composition: terrestrial planets. 4  Transmitted from structures on the earth and not ...
The terrestrial planets Mercury, Venus, Earth, and Mars, sizes to scale. 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 composition, Earth-like.ercury, 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 composition, Earth-like.