Mons Huygens Mons Huygens Mons Huygens is the Moon's tallest mountain (but not its highest point). It is about high and is located in the Montes Apenninus. The Montes Apenninus were formed by the impact that created Mare Imbrium. Adjacent is Mons Ampère to the west. Further west is the crater Huxley. The mountain was named after the Dutch astronomer, mathematician and physician Christiaan Huygens, it was officially named by the IAU in 1961. Mons Huygens is high, about the same height as Aeolis Mons located on Mars in the middle of Gale crater, and taller than Mons Hadley located on the
Solar System icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune. Most of the planets in the Solar System have secondary systems of their own, being orbited by planetary objects called natural satellites, or moons (two of which, Titan and Ganymede, are larger than the planet Mercury), and, in