I f astronomers had been walking the Earth 466 million years ago, they may have had something special to see. The moon and ...

A ring could explain a mysterious arrangement of impact craters near the equator and might even have caused an ice age, ...

People in ancient Mesopotamia depended on rivers. But rivers sometime moved, imposing stress on communities. Research shows ...

A new study co-led by the Smithsonian and the University of Arizona offers the most detailed glimpse yet of how Earth’s ...