(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?

The findings are part of a study about Pluto and its internal structure published Monday in the journal Nature Astronomy. Previously, the team studied unusual features across the solar system ...

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 ...

New research suggests the Oort cloud, a shell of icy objects at the edge of our solar system, may feature spiral arms similar to the Milky Way, revealing a complex cosmic structure beyond Pluto.