CAPE CANAVERAL, FL -- Come Tuesday, Clyde Tombaugh will pass within 7,800 miles of the icy world he discovered 85 years ago. His ashes are flying on NASA's New Horizons spacecraft on humanity's first ...

For generations Pluto stood as the mythic ninth planet until a scientific revolution shattered that legacy and transformed it ...

Today, the dwarf planet Pluto orbits the sun from the edge of our solar system and its surface temperature is an inhospitable negative 378 to negative 396 degrees Fahrenheit. But a new study suggests ...

Pluto was reclassified as a dwarf planet in 2006 when the IAU redefined what it means to be a planet, declaring that a planet must be a celestial body that orbits the sun, is round or nearly round and ...

Journey beyond Neptune to uncover the frozen, mysterious worlds that challenge everything we thought we knew about the solar ...

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 ...

Clyde Tombaugh noticed a speck of light that was Pluto in 1930. — -- Clyde Tombaugh is finally getting to visit the speck of light he spotted at the edge of the solar system in 1930. New Horizons ...