Pluto’s heart-shaped feature, known as Tombaugh Regio, has captivated scientists and the public alike since its discovery.

The debate over Pluto’s planetary status has been ongoing since its reclassification as a “dwarf planet” in 2006 by the ...

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 ...

Pluto, discovered 90 years ago on Feb. 18, 1930, was long considered the solar system's ninth planet. Although small, it orbits the sun and has the spherical shape required to be considered a planet.

Today in the history of astronomy, our solar system's ninth member is downgraded to a dwarf planet.

New Horizons has been carrying science instruments on its 3 billion mile, nine-and-a-half year journey to Pluto, and an ounce of the astronomer's ashes have also been along for the ride.

"People, children especially, have been baffled, bewildered, and even outraged by the fact that Pluto is no longer called a planet. Through whimsical artwork and an entertaining dialog format, this ...

The science community may be ecstatic over the discovery of a ninth planet, but the former planet "Pluto" had a totally different reaction.