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

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

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 ...

But I think this is also a great moment to pause and—maybe for folks whose immediate reaction to Planet Nine is something like “We already have a ninth planet. It’s Pluto. How dare they?”— ...

Astronomers believe that our solar system may still hold surprises, with ongoing efforts to find a hidden ninth planet, often referred to as Planet Nine or Planet X. If confirmed, this discovery ...

How many planets are there? As with the discovery of Uranus, the answer depends on who you ask. Detail from Joseph Wright of ...

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

A celestial body recently discovered by a Chinese observatory has been confirmed as a comet by the International Astronomical Union IAU Astronomers ...

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 ...

What is the ninth house, and what can it tell you? Ahead, more information on this specific house, its meaning, and how it corresponds to your zodiac sign. What are the houses in astrology?