The planet is almost 25,000 miles around and 4.54 billion years old, and humans are still discovering some of the amazing ...

Earth Day started in the 1970s. Here’s an Earth Day fact everyone should know: Earth Day was first observed on April 22, 1970 ...

A college student in a gas mask "smells" a magnolia blossom during the first Earth Day on April 22, 1970 in New York City. Credit - AP More than 8 billion people inhabit Earth, and soon a springtime ...

Ah, Earth. We may not think about our planet on a day-to-day basis, but the world we live in is a pretty interesting place. The third rock from the Sun—and to this day, the only one with known ...