Pluto has long been one of the most controversial objects in our Solar System. For decades it proudly held the title of the ninth planet, only to be reclassified in 2006 as a dwarf planet. That ...

It used to be the farthest planet from the Sun in our Solar System, until it was declassified. It's an icy relic in the Kuiper Belt on the edge of our Solar SYystem, and has only been visited once, by ...