A stunning planet parade is now visible in the night sky. A planet parade is when several of our solar system's planets are ...

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

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 ...

We’ve learned a lot about poor, poor little Pluto — thanks to NASA’s New Horizons probe, which visited the dwarf planet in 2015. 1 - Instead of an ancient, inert rock, we’ve found an icy ...

He called this hypothetical world "Planet X." "In some ways, Pluto's more of a planet than some of the other established planets, like Mercury." ...

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 since the dwarf planet was first spotted, on Feb. 18 ...

Pluto was discovered at Lowell Observatory in Flagstaff, Arizona in 1930 and was considered our ninth planet until 2006. The International Astronomical Union reclassified Pluto as a dwarf planet ...

In the early 2000s the term “planet” wasn’t terribly controversial. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto all claimed that moniker. But then some pesky ...

If you answered "Pluto's planethood," your grasp of the astronomical is excellent. Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about ...

He called this hypothetical world "Planet X." "In some ways, Pluto's more of a planet than some of the other established planets, like Mercury." Lowell dedicated years to predicting the location ...