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, ...

The Giant Impact Hypothesis posits a Mars-sized planetesimal, Theia, collided with Earth approximately 4.5 billion years ago, resulting in the formation of the Moon from the ejected debris. Multiple ...

Grab-and-go missions to asteroids have provided some of the most scientifically valuable samples since the Apollo ...

Smithsonian researcher Wriju Chowdhury is part of an expedition searching for 4-billion-year-old crystals that could uncover the secrets behind Earth’s early history Emma Saaty A remote geologic ...

Earth turned faster at the end of the time of the dinosaurs than it does today, rotating 372 times a year, compared to the current 365, according to a new study of fossil mollusk shells from the late ...