Earth Day began as a protest in 1970, but its meaning has evolved. Here’s how it changed - and what it represents today.

Millions of people around the world will pause, at least for a moment, to mark Earth Day. The annual event is Wednesday.

It might sometimes feel like the days are starting to drag on, but scientists say that this isn't necessarily all in your head. In a new study, researchers from the University of Vienna and ETH Zurich ...

A brief look at how scientists define a day, why Earth’s rotation sets the length of our days, and how small variations can ...

Here’s what you’ll learn when you read this story: Your phone is probably right about you being late to work (again), because the length of a day has seen a slow, almost unnoticeable increase over the ...

But it was a senator from Wisconsin, Democrat Gaylord Nelson, who had the idea that would become Earth Day. Nelson had long ...

Add Yahoo as a preferred source to see more of our stories on Google. Rising sea levels are slowing Earth’s rotation, lengthening how long an average day lasts. And the current rate of increase to a ...

Earth Day, celebrated annually on April 22, is all about working to create a safe, sustainable environment. While you’re ...

Earth Day is celebrated across the country, and the globe, through the mobilization for environmental causes. While it may seem strange to think of a world without ecological awareness, there was once ...

See stunning photos of Earth taken from space by astronauts and robotic spacecraft, celebrating our home planet on Earth Day.

For all that scientists rightfully worry about the dangers of climate change, the environmental movement has come a long way ...

On Earth Day, EPA Southeast administrator urges citizens to enjoy the outdoors and learn about the work and projects the ...