Pluto.

* Date of discovery: 1930

* Average orbit: 3.7 billion miles or 5.9 billion kilometers.

* Diameter: 1,430 miles, or 2,301 kilometers.

* Length of day: 6 Earth days, 9 hours.

* Length of year: 248 Earth years.

* One known satellite named Charon

From 1979 to 1999, it was inside the orbit of Neptune.

Pluto’s odd tilt and trajectory are important factors in the change, if the change indeed is seasonally related. The planet’s orbit is more elliptical than any other in the solar system, and its rotational axis is tipped 118 degrees (Earth’s axis is tilted 23.5 degrees).

Just another Plutonian(sp) Summer?

From and more at MSNBC.