Astronomers have hoped for the existence of Planet Nine for years. Things were looking promising, but this discovery might ...

The celestial body's unusual orbit “implies that something extraordinary occurred" in the early days of the solar system—and ...

In 2003, NASA-funded researchers spotted what was then the most distant object discovered in our Solar System. The dwarf ...

Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's ...

For now, the outer reaches of our 4.6 billion-year-old solar system continue to be shrouded in mystery, with the classification of objects changing as scientists gain a new understanding of them ...

WASHINGTON, May 30 (Reuters) - Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet ...

For now, the outer reaches of our 4.6 billion-year-old solar system continue to be shrouded in mystery, with the classification of objects changing as scientists gain a new understanding of them ...

It's the earliest stage of planet formation ever seen by scientists. The new planetary system is taking shape around HOPS-315 ...