More than a 150 years ago, before Neptune was ever sighted in the night sky, French mathematician Urbain Le Verrier predicted the planet’s existence based on small deviations in the motion of Uranus.

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 outer solar system may hide a world astronomers have never directly seen, a planet several times heavier than Earth ...

The telescope will measure dark energy and mapping cosmic structures across vast regions. However, its exoplanet survey marks ...

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 ...

The monsters are multiplying. Just months after astronomers announced hints of a giant “Planet X” lurking beyond Pluto, a team in Spain says there may actually be two supersized planets hiding in the ...

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 ...

The planets are coming! The planets are coming! Only months after announcing the possibility of a 'Planet X' 10 times Earth's mass orbiting 250 times Earth's distance from the sun, a team of Spanish ...