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

The annual event celebrates the discovery of the little planet with a big heart and other scientific advances at Flagstaff, ...

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's ...

An international team of astronomers have been able to probe the atmosphere of an exoplanet like never before. Exoplanet ...