There are regions in Pluto where huge ice structures exist. Scientists finally think they know how they are formed. Scientists have solved one of Pluto's most puzzling mysteries. In 2015 ...

Instead of a barren ice ball, Pluto featured vast plains of nitrogen ice, jagged mountains made of water ice, and intricate networks of frozen canyons. Its heart-shaped region, informally called ...

The feature's strange shape was a hint that the dent's creator struck Pluto obliquely, rather than head-on. That led them to simulate a 700-kilometer-wide (435-mile-wide) object — a ball of ice ...

The secret to all of that activity is Pluto’s probable underground ocean. The water ice on the surface of the world suggests that there should be more water hidden below ground. Over the course ...

One mountain chain near Pluto’s equator is more than 2 miles tall. 2 - We knew Pluto was covered by ice. What we didn’t know: It’s covered with four types of ice — methane, nitrogen ...

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?

However, some scientists argue that Pluto should be considered a planet based on geological activity rather than orbital mechanics. NASA’s New Horizons mission revealed ice mountains ...

Pluto is in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is made primarily of ice and rock and has only one sixth the mass of Earth's moon, and one third its volume.