The first-ever "Mickey Mouse Clubhouse" exhibit at the museum will place visitors in a quest to prepare a surprise birthday ...

An amateur astronomer discovered Pluto 95 years ago today. The former planet will complete an orbit in another 153 years.

as captured by the New Horizons spacecraftJPL/NASA 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 humanity is a multi ...

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.