For the first time since Pluto was demoted, the idea of a true ninth planet is edging from speculation toward something ...

There could be a ninth planet in our solar system that's lying in wait to be discovered - and no, it's not Pluto. Our solar ...

This year NASA unveiled new discoveries beyond our solar system, the count has surpassed 6,000, with several thousands more ...

The James Webb Space Telescope detected an atmosphere on a lava-covered exoplanet, evidence that small planets close to stars ...

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, ...

The newly identified cluster of Kuiper Belt objects lies about 4 billion miles from the Sun, offering fresh clues about how ...

I recall as a child lying on the grass at night, gazing up at the stars, and wondering if any of those distant suns had planets orbiting nearby. I was not the first to do so, of course. The question ...

A tiny meteorite is rewriting what scientists thought they knew about the origins of our solar system. New evidence found in shavings from a meteorite known as Northwest Africa 12264 — a 50-gram (1.8 ...