Add Yahoo as a preferred source to see more of our stories on Google. A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than the ...

Scientists have recently proposed the existence of “Planet Y,” a hidden Earth-sized world that could be lurking in our solar system at a distance much closer than the hypothesized “Planet Nine.” This ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

For the first time since Pluto was demoted, the idea of a true ninth planet is edging from speculation toward something testable. Instead of restoring Pluto, researchers are closing in on a different, ...

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. Labelled as planet X, prominent astronomers ...

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, along with dwarf planets like ...

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 ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and planetary masses silently orbit their stars — sometimes thousands of astronomical ...

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 ...

Planet Nine is believed to be between five and 10 times the mass of Earth and would be orbiting the sun far beyond Pluto, at around 550 times the distance between Earth and the sun. Scientists have ...