When Neptune was discovered in 1846 scientists started to believe that there was a ninth planet, it seemed as though there was something pulling at Neptune. Many astronomers started looking for a ninth planet known as "planet X" Percival Lowell built an observatory in Flagstaff, Arizona. Lowell got to lead the search for the ninth planet in 1905. Lowell had a theory on where the ninth planet was located. The search wasn't too successful until Lowell's death in 1916.
The observatory resumed it's search in 1929, but know Clyde W. Tombauhg is leading the way for "planet X".Tombaugh knew about telescopes and astronomy already. He was fit for the job. On February 18, 1930 Tombaugh was looking at some space photos he had taken in January. He had seen a faint object , almost a dim light. He had studied the photos and he had seen that it had moved. "I have found planet X"! Tombaugh said.
Pluto and Charon
Scientists have learned some things about Pluto but not much. They know that Pluto is the farthest planet from the Sun so far and that Pluto is the smallest planet.
Pluto has a very unusual orbit Scientists say that it " lays on it's side" they say that because it spins vertically. You can fit Pluto in earth over 100 times. It also seems there is another planet pulling it into orbit.
Every 248 years (our time) Pluto comes inside Neptune's orbit. It stays at that point for twenty years. During that period of time Pluto is closer to the Sun than Neptune. When it is closer it has an atmosphere. As it moves back from the farthest point from the Sun it's atmosphere freezes and falls back into the surface of the planet.
It takes so long for Pluto to rotate around the Sun and it takes six earth days to equal one day on Pluto.
Pluto has one satellite named Charon , Charon is half the size of Pluto. Some scientists have called Pluto and Charon "the doubled planet" because they're so close in size. Scientists say that Charon is a moon pulled away from Neptune's gravitational field. People call Pluto one of the most unique and most mysterious planet out of them all.
For more information visit the following sites:
http://www.windows.ucar.edu/tour/link=/pluto/pluto.html
