Earth Day is April 22. The 43-year-old tradition, started in the spring of 1970, signaled the rise of the modern environmental movement.

Around 20 million people across the United States took to the streets to demand cleaner water, air, and the protection of forests.

In honor of Earth Day, the Giraffe Blog has put together 50 awesome facts about space, the atmosphere, the sea, and what's under the earth.

It's an easy reminder that our Blue Marble is an incredible place to live.