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

Clyde Tombaugh didn't set out to discover Pluto when he sent his sketches of the night sky to Lowell Observatory in Flagstaff ...

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 ...

This week’s hype around a “city-killing” asteroid possibly striking Earth raised the fears of many before the odds of impact ...

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

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 in the outer solar system. At such a critical moment in US history, we ...

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

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

Still that date will be one to circle on cosmic calendars. It takes Pluto slightly over 248 Earth years to orbit the sun, which means that on March 23, 2178, one Plutonian year will have elapsed ...

Pluto did not meet all three criteria the IAU determined were necessary to be considered a planet: The body must orbit its host star, just as Earth and Jupiter orbit the sun. It is large enough to ...