Pluto is the least studied planet of the Solar System. It has a diameter of approximately 3000 kilometers.
Tiny Pluto is considered the coldest planet in the Solar System. Its surface is covered by a thick crust of ice, and the temperature drops to -200 0С. The ice on Pluto has a completely different structure than on Earth and is several times stronger than steel.
One year on Pluto lasts 248 Earth years. This means that while Pluto makes only one full revolution around the Sun, Earth manages to make 248.
In 2006, when the International Astronomical Union (IAU) formalized the definition of a planet, Pluto was transferred to the class of dwarf planets.
Pluto has five known discovered moons. It is the largest moon of Charon (discovered in 1978), Hydra and Nyctu (both discovered in 2005), Cerberus (discovered in 2011) and Styx (discovered in 2012).
