Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

Jupiter is the largest planet in the solar system, known for its massive size, strong gravity, powerful storms and many moons ...

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 ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact configuration and later underwent a violent reshuffling that scattered them to ...

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

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 ...

When 'Oumuamua traversed our solar system in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ...

Worlds will align for a "planetary parade" in January, with four bright and easily visible to the naked eye. But an even better view arrives in February and March. Here's what you need to know. When ...

Across the Milky Way and beyond, planetary systems appear to fall into a few recurring blueprints, and recent exoplanet ...

A new Tatooine-like planet outside the solar system may orbit two failed stars, scientists reported Wednesday. Located about 120 light years away, the exoplanet appears to take an unusual path around ...

With sapphire waterfalls, lava rain and orbits around dead stars, these distant worlds push the limits of what’s possible.