About 4.5 billion years ago, the most momentous event in the history of Earth occurred: a huge celestial body called Theia collided with the young Earth. How the collision unfolded and what exactly ...

Imagine compressing all of Earth’s 4.5-billion-year history into a single calendar year. In this model, midnight on January 1st represents the formation of Earth. December 31st at midnight is the ...

We live in a rapidly warming world. Immense volumes of human-generated greenhouse gases are nudging Earth’s climate to a warmer and warmer state, further changing our planet as sea levels rise, living ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration of Earth 200 million years ago as Pangaea, the last supercontinent, began to break apart. The continents we live ...

A new analysis of rocks thought to be at least 2.5 billion years old helps clarify the chemical history of Earth's mantle -- the geologic layer beneath the planet's crust. The findings hone scientists ...

Tiny bits of Earth’s atmosphere have been drifting to the moon for billions of years, guided by Earth’s magnetic field. Rather than blocking particles, the magnetic field can funnel them along ...

Getting your Trinity Audio player ready... Editor’s note: The opinions of the smart, well-read women in my Denver book club mean a lot, and often determine what the rest of us choose to pile onto our ...

A thin slice of the ancient rocks collected from Gakkel Ridge near the North Pole, photographed under a microscope and seen under cross-polarized light. Field width ~ 14mm. Credit: E. Cottrell, ...