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

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 ...

Earth is the only life-supporting planet in our Solar System. Until now. Today, we’re bringing Kepler 22-b into our planetary ...

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

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...