Mercury (planet)
Mercury is one of four terrestrial planets in the Solar System, and is a rocky body like Earth. It is the smallest planet in the Solar System, with an equatorial radius of . Mercury is also smaller—albeit more massive—than the largest natural satellites in the Solar System, Ganymede and Titan. Mercury consists of approximately 70% metallic and 30% silicate material. Mercury's density is the second highest in the Solar System at 5.427 g/cm, only slightly less than Earth's density of 5.515 g/cm. If the effect of gravitational compression were to be factored out from both planets, the materials of which Mercury is made would be denser than those of Earth, with an uncompressed density of 5.3 g/cm versus Earth's 4.4 g/cm.
List of nearest exoplanets
Most known nearby exoplanets orbit close to their star and have highly eccentric orbits. A majority are significantly larger than Earth, but a few have similar masses, including two planets (around YZ Ceti, 12 ly) which may be less massive than Earth. Several confirmed exoplanets are hypothesized to be potentially habitable, with Proxima Centauri b and three around Gliese 667 C (23.6 ly) considered the most likely candidates. The International Astronomical Union took a public survey in 2015 about renaming some known extrasolar bodies, including the planets around Epsilon Eridani (10.5 ly) and Fomalhaut.