Number of satellites: 1 the most important, 2 very small discovered by the Hubble Space Telescope in 2006.
The story of Pluto, its discovery
For Adams and Le Verrier, Neptune was the solution. For generations of astronomers who followed would become a problem.Once the path of Neptune was established with reasonable accuracy became clear that the eighth planet could not explain all the discrepancies between predicted and actual orbits of Uranus.
It was Percival Lowell from his own observatory who initiated the search for the ninth planet in 1905. Picketing who accompanied the search Lowell called it Planet O. The letter in the alphabet follows the N (in a display of originality initial Neptune). In 1919 he predicted that this was between the constellations Taurus and Gemini are not performing well in the search is postponed it for almost ten years when it appears in the Centre now equipped with a 23 cm refractor telescope, a 22 year old Clyde Tombaugh .
Clyde Tombaugh, who discovered the planet Pluto.
Tombaugh spent whole nights photographing Gemini but his supervisor did not wait for the meeting came to find what is really hiding in these plates. On February 18, 1930 Tombaugh discovered Pluto while it was not until March 13 of that year when the Observatory Flagstaff the news made public in May and was given the name by which it is known today.
There, on the borders of the solar system where radiation from the Sun is about 1,500 times less than on Earth. While the orbits of other planets are no more than seven degrees off the ecliptic plane, Pluto orbits the Sun on a trajectory tilted over 17 °. The eccentricity of its orbit makes cyclically, as happened in 1979 until 1999, Pluto is closer to the Sun than Neptune.
The dwarf planet Pluto now called by the IAU and its moon Chiron and Chiron. (Credit NASA, Hubble Space Telescope).
Your status as a planet was based almost entirely on the fact that an atmosphere and a moon. Now, as we know, was stripped of his status of planet to become a Dwarf Planet.
The knowledge currently has on this body cold and distant, very few, no probe has yet explored. The New Horizons spacecraft sent by NASA in 2006 to explore just come to him in 2015 will cover 6,400 million kilometers and it will take 9 years.
New Horizons is the fastest spacecraft launched from Earth so far, has been in charge of art elements such as infrared and ultraviolet spectrometers. In the year 2007 was to reach Jupiter, used the gravity of this giant planet as a catapult to Pluto. In predictable to achieve the dwarf planet by mid-2015. You may expect us many interesting surprises when the probe reaches the vicinity of Pluto, will test and analysis instruments carried on board. Curiously, the ship also carries ashes of its discoverer, Clyde Tombaugh.
Diameter in miles: 2,000
Dia / Land: 0.36
Ground / Earth: 0.002
Gravity / Earth?
Ecuador inclination to the plane of the orbit of the planet: 120 º
Sidereal rotation period in days, hours, minutes and seconds: 6 hours, 9 minutes, 18 seconds
Distance to Sun in million km: Minimum: 4,425 / Max: 7,375 / Media: 5,900
Distance to the sun in UA (average distance): 39.3
Tilt the plane of the planet's orbit about the Earth: 17 º 10’
Sidereal period of revolution in Years, Days and Hours
Year 247/249 Days / 6 Hours