Pluto, Pronunciation /?plu?to?/ , formal designation 134340 Pluto, is the tenth-largest body observed directly orbiting the Sun. Classified as a planet from its 1930 discovery, in 2006 the International Astronomical Union (IAU) declared it a dwarf planet instead; Pluto is composed primarily of rock and ice and is relatively small: approximately a fifth the mass of the Earth’s Moon and a third its volume. It has an eccentric and highly inclined orbit that takes it from 30 to 49 AU (4.47.4 billion km) from the Sun. This causes Pluto to periodically come closer to the Sun than Neptune. Pluto and its largest moon, Charon, are sometimes treated together as a binary system because the barycentre of their orbits does not lie within either body. The IAU has yet to formalise a definition for binary dwarf planets, and until it passes such a ruling, they classify Charon as a moon of Pluto. Pluto has two known smaller moons, Nix and Hydra, discovered in 2005. From its discovery in 1930 until 2006, Pluto was considered the Solar System’s ninth planet. In the late 1970s, following the discovery of minor planet 2060 Chiron in the outer Solar System and the recognition of Pluto’s very low mass, its status as a major planet began to be questioned. Later, in the early 21st century, many objects similar to Pluto were discovered in the outer Solar System, notably the scattered disc object Eris, which is 27% more massive than Pluto. On August 24, 2006, the IAU defined the term “planet” for …
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02Oct
Posted by Pluto @ 9:36 pm
Tags: astronomy, charon ploutos moon, clyde tombough, dwarf planet, esa, Horizon spacecraft, kurd, kurdistan, moon, NASA, Planet Pluto, planet x, planets, Pluto and charon, solar system, space, space exploration, trans neptunian objects