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 ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system? When you purchase through links on our site, we may earn an affiliate commission. Here’s ...

Earth may have a moon today because a nearby neighbor once crashed into us, a new analysis of Apollo samples and terrestrial rocks reveals. When you purchase through links on our site, we may earn an ...

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 ...