Scientists say studying objects like Ammonite, despite their immense distance, offers valuable insight into the solar ...

Planet 9 sits at the edge of scientific imagination, promising either an epic expansion of the Solar System or a lesson in ...

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 ...

China advances plans for dual solar system boundary missions China has published coordinated papers outlining dual missions ...

The official number of exoplanets—planets outside our solar system—tracked by NASA has reached 6,000. Confirmed planets are added to the count on a rolling basis by scientists from around the world, ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

The number of confirmed planets outside of our solar system—known as exoplanets—has risen to 6,000, NASA has said. There is huge variety across these distant worlds, the space agency says, with ...

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 ...