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 ...

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 ...

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 ...

In our solar system, Jupiter is the undisputed king. If you added more mass to Jupiter, it wouldn’t actually get much bigger ...

When astronomers first observed comet 3I/ATLAS, they realized it was special. It is just the third confirmed interstellar object to pass through our Solar System, after the enigmatic ‘Oumuamua and the ...

All of our solar system’s planets are lining up in the night sky at once this week. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a great ...

The 2026 planetary parade is a powerful reminder of our place in the solar system. While these planets aren't actually "lining up" in space, their visual alignment from our perspective on Earth is a ...

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 ...

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 ...