Legend has it that somewhere beyond Neptune and Pluto, there is a ninth planet, with a mass that is five times greater than ...

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 curious minds at What If explore what would happen if all the planets were knocked off course, revealing collisions, chaos, and cosmic devastation.

General relativity helps explain the lack of planets around tight binary stars by driving orbital resonances that eject or destroy close-in worlds. This process naturally creates a “desert” of ...

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 ...

An exciting new study titled "Soot Planets instead of Water Worlds", by Jie Li and associates, published in August 2025, challenges prevailing assumptions about the nature of many low-density ...

A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is hidden in our solar... If Planet Nine is out there, this telescope might ...