Space has a knack for bending our sense of scale. The Moon feels close enough to touch—after all, we see its craters with ...

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 ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

Astronomers might have found evidence of a structure located farbeyond Neptune, potentially giving us clues about the solar system’s primordial past. This discovery involves a dense concentration of ...

"We have been calling Uranus an ice giant, but we don't really know its nature." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Astronomers say ...

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 ...

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 ...

Ian Whittaker does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...