Could a lonely planet wander aimlessly through the restless galaxy change the subtle dance of gravity within our solar system ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and Earth. The authors dubbed it Planet Y.

In a groundbreaking discovery, astronomers have confirmed the approach of a “wandering planet” into our solar system. This ...

Space scientists look back on 30 years of exoplanet discoveries — from rows of massive ‘super-Earths‘ to worlds with ...

Our solar system is a smashing success. A new study suggests that from its earliest period—even before the last of its ...

Sky gazers across the U.S. will have a chance to see an extraordinary celestial event on Friday as all of the planets in our solar system will appear in the evening sky. This phenomenon known as a ...