Something strange is happening on the outskirts of our Solar System. It could be a large, mysterious planet. Or, it could be ...

What is Planet Nine, and where is it? The question has fascinated astronomers for years. Scientists believe a massive undiscovered planet may exist in the outer Solar System. Although no telescope has ...

While life on Mars (and Venus) has long been an obsession for those wondering if we're alone, there are other places in our ...

The hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. Some astronomers ...

On a clear night, it dominates the sky, bright enough to cast shadows and large enough for dark patches and surface features ...

Some researchers see in this population the manifestation of an invisible presence, a new planet not yet discovered in the dark and cold confines of our solar system. Others, however, think that there ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Pluto hasn't been a planet for almost 20 years. In the early 2000s, scientists discovered several objects of a similar size to Pluto. So, during the summer of 2006, members of the International ...

CAPE CANAVERAL, Fla. — Astronomers have discovered a rare solar system in the Milky Way that boasts six planets orbiting in perfect rhythm like a cosmic orchestra, untouched by outside forces since ...

A village in Kent is home to what is thought to be the world's largest scale model of the solar system and beyond, created to ...