Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

On the 95th anniversary of its discovery, Pluto remains one of the most beloved and enigmatic worlds in our solar system, ...

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

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to ...

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

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

February 18th has been a significant date throughout history, marking a variety of events that have shaped the world. In a ...

Scientists at NASA for the first time have been able to observe the make up of Pluto and other small and icy celestial bodies ...

Tombaugh's photos that led to the discovery of Planet X. Pluto never really fit in with the other planets in the solar system. Its orbit was out of plane with the other planets. From 1979 to 1999 ...

Saturn, Venus, Neptune, Uranus, Jupiter, Mars and Mercury will be visible in an uncommon planetary alignment this month.

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...