Pluto's days, though they drag on a bit at around 153 hours, are nothing compared to its years. Pluto's orbit takes 248 Earth ...

The science community may be ecstatic over the discovery of a ninth planet, but the former planet "Pluto" had a totally different reaction. Hours after scientists announced there's solid evidence of ...

Pluto’s heart-shaped feature, known as Tombaugh Regio, has captivated scientists and the public alike since its discovery. This striking geological formation offers insights into the unique ...

(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? If ...

FLAGSTAFF – Clyde Tombaugh sat in the Orpheum Theater that fateful night in February 1930, waiting for clouds to pass before the 24-year-old astronomer could return to Lowell Observatory to confirm ...

The International Astronomical Union declared that Pluto only fulfills two of the three criteria for a full-size planet. Pluto, discovered 90 years ago on Feb. 18, 1930, was long considered the solar ...

A team of researchers affiliated with several institutions in the U.S. and one in France has found evidence of ammonia on the surface of Pluto. In their paper published in the journal Science Advances ...