(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague?

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto turns out to have as much complexity as Mars or Earth, so much so that I ...

Gender: Male Age: 1 year 7 months Weight: 51 pounds Species: Dog Breed: Rhodesian Ridgeback – Brown Orphaned Since: April 9 Adoption Fee: $250 Meet Pluto, a 1-year-old Rhodesian Ridgeback whose ...

There are eight planets in our solar system – plus poor old Pluto, which was demoted in 2006 – but what if there were more? Turns out that might be the case. Astronomers have calculated there ...

This would be a real turn-up for the books as, until now, astronomers thought Pluto was too old to have retained enough heat energy to have these processes occurring. It might mean all sorts of ...

Pluto was discovered 95 years ago on Feb. 18, and even though it was demoted nearly two decades ago, it remains a fascinating part of our solar system. "Pluto is a complex and mysterious world ...