A low-density, puffy planet orbiting relatively far from a young star in a nearly perpendicular orbit. What's going on?

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

Did you know our solar system might have had an extra planet? Scientists believe a mysterious ninth planet once existed but got kicked out long ago! This "lost" planet could have been tossed into deep ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from Taiwan, ...

We all need some space sometimes—but it's harder to find than you might think. How far into our universe do we have to go to ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

The James Webb Telescope captures the beginning of planetary formation around the young star HOPS-315 for the first time.

This is an image of Ceres, the nearest dwarf planet to Earth in the solar system. A new dwarf planet extremely far from the sun may have just been discovered. Credit: NASA / JPL-Caltech / UCLA / MPS / ...