Many scientists knew that Neptune alone could not
account for Uranus's side-tracking of its predicted
path. An astronomer Clyde Tombaugh spent thousands of
hours looking through photographs until in 1930, his
perserverence was rewarded when he found a photograph
showing Pluto. Pluto was only vivited by Pinoeer 10, so
there is very little information on it.
APPEARANCE OF PLUTO
Observations showed that the surface is covered by the frozen water and Methane at about -230 degrees celsius. It is just basically a ball of rock encased in ice and has a rather bluish shade of colour.
FURTHEST FROM THE SUN?
Pluto is usually described as the furthest planet from the sun, however, this is not always true. Its orbit sometimes takes it nearer to the sun than neptune as its orbit is such a stretched as an eclispe as shown in the picture below.