Rocky Exoplanets

Small, dense worlds with solid surfaces, similar in composition to Earth, Venus, and Mars.

Rocky exoplanets, sometimes called terrestrial planets, are defined by having a radius of 1.25 Earth radii or less (or a mass under 2 Earth masses when radius is unknown). These compact worlds are composed primarily of silicate rocks and metals, with thin or negligible atmospheres. They are the most Earth-like category of exoplanet and are prime targets in the search for habitable worlds. Many rocky exoplanets are found orbiting red dwarf stars, where the habitable zone is much closer to the star than in our solar system.