12. How Cold Is Pluto?

It’s colder than you can imagine on Pluto, hundreds of degrees below zero. Visit the observatory where Pluto was discovered to see the unusual machine that spotted the tiny planet. Pluto is the only major body in the solar system not yet explored by a space probe but we get a clue to what it might be like by looking at another interesting place, a frozen moon called Triton, which orbits around Neptune. Ice volcanoes and a super-cold bizarre landscape awaits explorers. Pluto is not the only frozen world out there. Deep in the outermost realm of the solar system is a whole swarm of ice balls—most of them small, but some half as big as Pluto is known as the Kuiper Belt. Pluto is the largest member of these ice worlds. But some folks wonder if it deserves to be called a planet at all!