Scientists have been wondering for years whether there is a ninth planet in our solar system. Now, a study by Japanese scientists seems to bust that belief. They have found an object orbiting the Sun ...

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 ...

While Pluto has long since been relegated from the official lineup, astronomers have now seemingly confirmed suspicion of another planet in our solar system, and it could even potentially be home to ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

Somewhere at the edge of the solar system a new Earth-sized world might be lurking, dubbed Planet Y. Astronomers have long proposed that there might be hidden planets beyond the Kuiper belt, a region ...

It's easy to think that Neptune is the coldest planet in the solar system because it is the farthest from the Sun. Astronomers have been puzzled for years by the fact that Uranus is the coldest planet ...

Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

This latest study, published in the science journal arXiv, says a warping effect which was picked up in the orbits of some Kuiper belt objects suggests an undiscovered planet. According to ...

One of the interesting facts about our Solar System is how fast different planets spin on their axis. Earth takes about 24 hours to make a full rotation, but some planets spin much quicker, making ...