Pluto is the farther planet from the Sun, but due to the odd behavior of its orbit, it gets nearer than Neptune for 20 odd years out of its 249 Earth year orbit. It is the second biggest known dwarf planet but the tenth largest orbiting the Sun. It was discovered in 1930 to the year 2006 it was thought to be the ninth planet in our solar system, but there have been some more discoveries after that.

International Astronomical Union named officially named the ninth planet Pluto in 1930 after the Roman god of the underworld. Pluto is the only and first planet to be discovered by an American, an astronomer called Clyde W. Tombaugh. Even though discovery of Pluto was made way back in 1930, there is inadequate information about this far off planet.

But even without close examination we are aware of the fact that it is a very cold planet or rather a frozen one whose surface is in most likelihood composed of crystallized nitrogen. It has a very tenuous atmosphere.

The pressure on Pluto is 100,000 than the sea level on our planet and consisting of mostly nitrogen with some traces of carbon monoxide and methane. The space craft New Horizons was initiated on January 16, 2006 and will make will be closest to Pluto around July 14, 2015. This will give more clarity on the characteristics of this odd dwarf planet.

Pluto and its satellites rotation period is 6.387 Earth days. Although it is not uncommon for a satellite to tour in a simultaneous orbit with its planet, but here Pluto rotates concurrently on the orbit of its satellite Charon. As a result Pluto and Charon all the time face each other traveling through the space. The atmosphere of Pluto changes according to its distance from the sun as Pluto's eccentric orbit fluctuates between 4000 and 7000 million kilometers.

Like Uranus but unlike most other planets, Pluto rotates with its poles roughly in its orbital plane. The rotation axis for Pluto is tipped at 122 degrees. At the time of discovery it s comparatively bright south polar was seen from the Earth , but Pluto seemed to become duller as the viewpoint slowly changed from near the pole-on in 1954 to almost the equator-on in 1973. At present we can see Pluto's equator from Earth.

Earth was aligned with the orbit of Charon along with Pluto from 1985 to 1990; this gave our astronomers a good chance to gather important data which led to the first precise calculation of Pluto and Charon size and other vital information.

At one time it was known as the smallest, coldest, and furthest known planet from the Sun, but Pluto has double characteristics, and has been surrounded by controversy since it was discovered in 1930. According to the new rules the planet did not meet the requirements of being a planet so on August 24, 2006, the International Astronomical Union officially downgraded Pluto from planet to a dwarf planet.