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 ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...

In a groundbreaking discovery, astronomers have confirmed the approach of a “wandering planet” into our solar system. This celestial event has sparked a flurry of scientific interest and speculation.

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 ...

LONDON — 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 ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't ...