Billions of years ago, so the theory goes, something around the size of Mars smacked into Earth, spewing a whole bunch of dirt into space that eventually coalesced to form the Moon.

Despite having the wrong ideas about how the Moon’s craters formed, these 19th-century astronomers created highly accurate ...

From this evidence, they came to the conclusion that the moon must have been formed out of debris knocked loose when a celestial body slammed into the young Earth. This theory was popular because ...

The South Pole-Aitken basin is the moon's oldest and largest visible crater—a massive geological wound 4 billion years old ...

Since the 1980s, the predominant theory has posited that the Moon formed from debris following an explosive collision between early Earth and a protoplanet named Theia. However, a new study by ...

Earth's "second moon" won't be sticking around for Thanksgiving, but just as many of us will on Thursday (Nov. 28), it seems ...

Subscribers may view the full text of this article in its original form through TimesMachine ... regarding the recent eclipse of the moon. View Full Article in Timesmachine » Advertisement ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Scientists have ...

For years, scientists believed this enormous crater was formed by an object striking the moon from a shallow angle, possibly as extreme as a rock skipping across water. Under this theory ...