Scientists widely agree that an ancient planet likely smashed into Earth as it was forming billions of years ago, spewing debris that coalesced into the moon that decorates our night sky today. The ...

After its debut in the United Kingdom, "Planet Earth III" will soon be available to stream in the U.S. The third iteration of the smash hit natural history series "Planet Earth" continues its ...

Earth may have a moon today because a nearby neighbor once crashed into us, a new analysis of Apollo samples and terrestrial ...

Since the beginning of Earth's history, tiny particles of rock and metal from space have been hitting our planet. On clear nights, we can even see their traces as shooting stars. Trapped in layers of ...

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

The Great Oxygenation Event, which occurred around 2.4 billion years ago, was one of the biggest transformations of our planet. Before it, there was practically no oxygen in the atmosphere; after, ...

Millions of people around the world will pause on Tuesday, at least for a moment, to mark Earth Day. It's an annual event founded by people who hoped to stir activism to clean up and preserve a planet ...

A collision between Earth and a massive Mars-sized protoplanet likely caused the formation of our moon. Now scientists from the Max Planck Institute suggest that ...

By trapping huge amounts of water on land, big dams built by humans have slightly changed how Earth spins and where its poles ...

Life made the modern Earth as much as the Earth made life, a new book by a philosopher of consciousness argues. That dynamic leaves humans with a unique set of moral questions, Peter Godfrey-Smith of ...

Mars changed from a blue world with water to a red desert because its atmosphere escaped into space over billions of years.