The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a ...

If Brown’s hidden world is real, Rubin will almost certainly find it or strong indirect evidence that it exists. “In the ...

A few decades ago, the Solar System had nine planets, but in 2006 the International Astronomical Union reclassified Pluto as ...

The concept of Planet X, or Planet Nine, has captivated astronomers for decades. This hypothetical planet, theorized to be ...

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

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?

A very rare treat is about to grace Earth's night skies.

Unless you’re really on the low end of our listener age bell curve, chances are you grew up learning about our solar system’s nine planets. Of course, unless you’ve been living under a rock ...

NASA's Director of Planetary Science, Jim Green, discusses the Jan. 20 2016 Astronomical Journal science paper that points to ...

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 ...