Pluto

Pluto means:
In astronomy mythology, Pluto was thought to be the god to whom all men must eventually go. Romans believed him to be the god of the underworld. His name in Greece was Hades.

How much would you weigh on Pluto?
Because Pluto is so small you would be very light if you visited. If you weigh 70 pounds on Earth, you would only weigh 4 pounds on Pluto.

The Planet:
Pluto is smaller than 7 of the moons in the Solar System.  Because it is so small many scientists don't consider it a planet at all.  In 1999 a group of scientists attempted to redesignate Pluto as a comet. 
Pluto is the only planet that has never been visited by space craft.  Because we have never sent probes to this planet we know very little about it. 

Moons:
Pluto has one moon named Charon.  Charon is only slightly smaller than it's parent planet Pluto.  For this reason Pluto and Charon are often called double planets.  The Earth and it's moon Luna are also considered double planets.