Science glossary film: Terrestrial planets

Also called rocky planets, the planets in our Solar System composed mostly of silicate rocks, and the innermost of the eight planets in our Solar System. All have similar structures: a central metallic core, surrounded by a rocky mantle. In looking for planets around other stars, most found so far are gas giants, as they are the easiest to detect. But since the early 1990s, astronomers have started to identify additional rocky planets.

All have similar structures: a central metallic core, surrounded by a rocky mantle. In looking for planets around other stars, most found so far are gas giants, as they are the easiest to detect. But since the early 1990s, astronomers have started to identify additional rocky planets.