Thanks to the discovery of thousands of exoplanets to date, we know that planets bigger than Earth but smaller than Neptune orbit most stars. Oddly, our sun lacks such a planet. That's been a source ...

New images released Wednesday from NASA's James Webb Space Telescope are revealing Neptune, and the planet's hard-to-detect rings, in a fresh light. "It has been three decades since we last saw these ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...