Pluto will mark a birthday of sorts on March 23, 2178. No one is likely to be there to celebrate it, of course. Even if ...

Pluto is too far away from Earth to be seen with the naked eye. If you stood on Pluto's surface, the Sun would merely appear to be a very bright star. Although previous images showed that ...

Pluto is probably best known for being a demoted planet. In 2006, the International Astronomical Union stripped it of its original classification, after narrowing the definition of a planet to be ...