Pluto, planet of Scorpio
Pluto is the smallest planet in the solar system, a tiny world of ice and rocks with dimensions equal to two thirds of the Moon, it is usually the outermost planet, but also has a highly elliptical orbit that at certain times makes it close to the Sun Neptune.
It was discovered in 1930 by the American C. Tombaugh, who took over the existence beyond Neptune using a photographic method of research: Pluto is still mysterious because it has never been explored by a spacecraft.
Its surface should be covered with methane ice part of which evaporates originating a tenuous atmosphere temporary, lasting a few decades, the period of closest approach to the Sun, under the layer of methane ice would be found a layer of water ice and a large rocky core.
Charon was discovered in 1978 is the only moon of Pluto, about the size of half the planet has a mass equal to one-fifth that of Pluto, in fact, throughout the solar system there is a satellite so large compared to their planet, in fact the two bodies can be considered a double planet.
Charon orbits at a distance of 18400 km from Pluto in about 6.4 days.
Each planet and satellite rotate around its own axis with the same period and therefore will always show the same face each other: the observation of Pluto which has magnitude equal to 14 only, is difficult because it is needed a telescope at least 20 centimeters in diameter for just see it, and even larger telescopes Pluto looks like an insignificant point of light like a star and you can not find any surface structure.
The easiest way to track it is following in his motion against the backdrop of a star field through a series of photographic images, this criterion led to Clyde Tombaugh.
Its orbit is inclined by 17 ° relative to the Earth moves away from the ecliptic and therefore more than any other planet.
Pluto was recognized as a god in the ancient myths of the beyond the grave, ruling the sign of Scorpio, was residing in the Underworld where mortals punished for their misdeeds, but also decided who should live or die by his wife, who walked the streets of the world looking for people to touch as he carried the candle light of this world, they say if you were turned off, no one could die any more, but would be forced to live forever under immense sufferings as the body continued to fall apart without destroying altogether.