Our Solar System has eight planets, a few dwarf planets and more than 200 moons. But wait. Are you seeing double? Or did ...

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

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

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 ...

When 'Oumuamua traversed our solar system in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't been for lack of trying. According to a new paper by Thomas Winterhalder of ...

A new study suggests that our solar system’s smallest planet has shrunk by up to 30 percent since its birth roughly 4.5 billion years ago ...

Add Yahoo as a preferred source to see more of our stories on Google. About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong ...

Learn how Pluto nearly kept its planet status in a proposed 12-planet Solar System as its demotion marks its 20th anniversary. Eight days before Pluto lost its planetary status, it appeared ready to ...