Pluto is known as the planet furthest away from the Sun. However, due to its highly eccentric orbit, it is closer than Neptune for twenty of its 249-year orbit. In modern times, Pluto has been closer to the Sun than Neptune since January 1979 to February 11, 1999. During this time frame, Pluto was closest to us on September 11, 1999. This event will not occur again until September 2226.
As Pluto reaches its perihelion, it is at maximum distance due from its elliptical orbit because of its 17-degree inclination. This means that Pluto will never collide with Neptune. In fact, their closest approach distance is 18 astronomical units.
Pluto has an orbital period exactly 1.5 times longer than Neptune (ratio of 3:2) and has a rotational period of 6.387 days. Interestingly, it rotates not only in synchronous orbit with its moon, Charon, it rotates synchronously with the orbit of Charon. Like the Earth and the Moon, Pluto and Charon are tidally locked, thus continually facing each other.
Pluto also has a peculiar rotational axis. It is the only planet (besides Uranus) to rotate with its poles in its orbital plane, being tilted 122 degrees. Thus, when the planet was first discovered, observers first noticed a bright south polar region. As the planet continued on its tilted orbit, Pluto's equator became the head-on view (1973). Another interesting fact is that Pluto rotates in the direction opposite from most of the other planets.
Pluto's Orbit 
