NASA on Friday released its first glimpse of a strange mosaic of ice on Pluto. WSJ's Robert Lee Hotz reports. Photo: NASA/JHUAPL/SwRI ...

(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 is too far away from Earth to be seen with the naked eye. If you stood on Pluto's surface, the Sun would merely appear to be a very bright star. Although previous images showed that ...

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 ...

NASA's New Horizons spacecraft conducted the first and only flyby of the Pluto system, culminating at the closest approach of that distant world in July 2015. Sailing onward, the probe carried out ...

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 ...