Five years ago, astronomers revealed a spectacular collection of other worlds: the TRAPPIST-1 system. Newspapers around the world printed the discovery on their front pages: Astronomers had found that ...

Thousands of planets have been discovered beyond our solar system, offering clues to where life might thrive and whether ...

Add Yahoo as a preferred source to see more of our stories on Google. A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than the ...

In a recent paper, Harvard researchers found that raindrops are remarkably similar across different planetary environments, even planets as drastically different as Earth and Jupiter. Understanding ...

The shape of a planet's orbit is one of its fundamental properties, along with its size and distance from its host star. Earth has a nearly circular orbit, but some planets outside our solar system, ...

Mercury has been shrinking since it formed in our solar system's early days. New evidence, though, suggests it used to be ...

But what exactly is a planet? It seems like an easy question. After all, you’re standing on one right now! But the scientific ...