Pluto has the most eccentric orbit of all the planets in the solar system. Usually the 9th planet, Pluto gets to be the 8th planet for roughly 20 years at a time as its passes within Neptune's orbit.

Pluto became the 8th planet in January 1979 and will be the 8th planet until February 1999. In addition to its peculiar orbit, Pluto and its moon Charon are locked together as they orbit each other, so that the same side of each body always faces the other and neither gets to see the back of the other's head.

It takes 248 years for Pluto to complete its orbit. This means that a single Pluto year is 248 Earth years long. When Pluto is in its normal position, it is about 9 (multiple of 3) light years from Earth.