A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and ...

There could be a ninth planet in our solar system that's lying in wait to be discovered - and no, it's not Pluto. Our solar system has eight planets but in recent years, astronomers have theorised ...

“Because Pluto is rotating rapidly prior to the collision, and because Charon lies mostly outside of their corotation zone, ...

The potential discovery of a large planet beyond Neptune’s orbit could change everything we know about the Solar System.

An curved arrow pointing right. Astronomers say they've discovered a ninth planet 200 times farther from the Sun than Earth. Produced by Emmanuel Ocbazghi. Original Reporting by Jessica Orwig.

Opinions expressed by Forbes Contributors are their own. Jamie Carter is an award-winning reporter who covers the night sky. Computer simulations suggest that there is an undiscovered Earth-like ...

We’ll finally get to meet the former ninth planet face-to-face—to really see its surface and that of its largest moon, Charon. Scientists have some guesses about what they might find ...

Astronomers are on the hunt for a mysterious ninth planet, known as Planet Nine, which could change our understanding of the solar system. Is this hidden world real, or just a myth?

For more than 70 years, Pluto was classed as the ninth planet but that changed in 2006, when the International Astronomical Union downgraded its status to that of a dwarf planet. Last September ...

She, like her fellow soldiers, do not remember anything about the Ninth Planet - their real memory has been erased, and false memories have been implanted instead.

This mysterious ninth planet could be found within the next ‘two years’, one expert said (Picture: Getty Images/iStockphoto) We’re closer than ever before to knowing whether there is a ninth ...