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 exceptional asteroids
Minor planets with orbital inclinations greater than 90° (the greatest possible is 180°) orbit in a retrograde direction. , of the more than 700,000 minor planets known, there are only 95 known retrograde minor planets. In comparison, there are over 1,920 comets with retrograde orbits. This makes retrograde minor planets the rarest group of all. High-inclination asteroids are either Mars-crossers (possibly in the process of being ejected from the Solar System) or damocloids. Some of these are temporarily captured in retrograde resonance with the gas giants.The above table lists only numbered asteroids that are also comets. Note there are several cases where a non-numbered minor planets turned out to be a comet, e.g. C/2001 OG108 (LONEOS), which was provisionally designated .