Planetary scientists have long debated where the material that formed Earth comes from. Despite its location in the inner ...

For years, planetary scientists have argued that some of the material that built Earth must have drifted in from beyond ...

Exoplanet L98-59d, located far beyond our solar system, might not sound like someone’s dream destination. It likely has an ...

A new analysis of meteorite isotopes challenges long-held ideas about Earth’s origins, suggesting our planet may have formed ...

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 ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...

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 ...

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 ...

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 ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...