As far-fetched as it may seem, quirks of orbital mechanics could allow hundreds of planets to be packed around a star ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

Planet 9 is the hypothetical ninth planet in our Solar System. Has it finally been found using IRAS and AKARI mission data?

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 ...

Imagine if the planet Jupiter orbited much closer to the Sun. What effect would a so-called hot Jupiter have on our Solar ...

Planet 9 would fall somewhere in between these categories. It could be what is known as a Super-Earth, a rocky planet larger than our own, or a sub-Neptune, a gaseous world less massive and slightly ...

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. A leading scientist has told Newsweek about new evidence supporting the ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Computer simulations suggest that there is an undiscovered ...

Astronomers have proposed Planet Y, a hypothetical world that could be orbiting unseen in the far reaches of our solar system. Find out more in this short video from EarthSky’s Will Triggs. Is Planet ...

For the first time, astronomers have detected radio signals from a planet beyond our solar system, according to a study available on the preprint server arXiv. The landmark observation offers a new ...

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 ...