Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Is there an unseen planet — a "planet X" or "Planet Nine" — ...

The Xai Foundation announced today that the treasure hunt extraction shooter Planet-X is joining the Xai blockchain system. It joins Xai’s roster of games and is currently in closed beta with a launch ...

We’re closer than ever before to knowing whether there is a ninth planet whooshing around the sun – and, alas, it’s not Pluto. Planet X, also called Planet Nine, is a hypothetical planetary body seven ...

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 ...

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 ...

A study recently submitted to The Astronomical Journal continues to search for the elusive Planet Nine (also called Planet X), which is a hypothetical planet that potentially orbits in the outer ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...