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.
PSR B1257+12 A
PSR B1257+12 b, alternatively designated PSR B1257+12 A, also named Draugr, is an extrasolar planet approximately 2,300 light-years away in the constellation of Virgo. The planet is the innermost object orbiting the pulsar PSR B1257+12, i.e. a pulsar planet in the dead stellar system. It is about twice as massive as the Moon, and is listed as the least massive planet (with the mass accurately determined) known, including among the planets in the Solar System.