CAPE CANAVERAL, Fla. – Vast frozen plains exist next door to Pluto’s big, rugged mountains sculpted of ice, scientists said Friday, three days after humanity’s first-ever flyby of the dwarf planet.

Eighteen years ago today, Pluto lost its planetary status in a vote by International Astronomical Union (IAU) members on the final day of their 2006 general assembly meeting. The word "planet" comes ...

Pluto might be small and distant, but it keeps surprising scientists. After the New Horizons spacecraft zipped past it in 2015, we got our first real look at its icy landscape and unexpectedly active ...