The status of Pluto not withstanding, our solar system has 8 planets, but one astronomer believes we used to have a ninth ...

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 ...

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 ...

Pluto is now the most well known of the outer worlds beyond Neptune—and the darling of the solar system Kayla Randall | Digital Editor, Museums A view of Pluto from NASA’s New Horizons spacecraft ...

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 ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

This voice experience is generated by AI. Learn more. This voice experience is generated by AI. Learn more. Pluto’s been making news again. Jared Isaacman, the head of NASA, recently suggested that ...

Twenty years after Pluto lost its planetary status, the debate continues as scientists still disagree over what defines a planet.

LONDON — 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 ...