Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

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 ...

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

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

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

The upcoming year will offer a blood-red moon, spectacular meteor showers and the first glimpse of the sun’s corona since ...

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 ...

Our Solar System has eight planets, a few dwarf planets and more than 200 moons. But wait. Are you seeing double? Or did ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon.