Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. There's a lot more to Earth ...

Earth Day began in 1970 and takes place on April 22 every year. Here are 10 questions to test your knowledge of the planet. 1. A day on Earth is 24 hours but it always hasn’t been that way. Are the ...

Do you consider yourself an environmentalist? A planet protector? A tree-hugging, composting, reusable-straw-carrying warrior of sustainability? Well, it’s time to put your environmental street cred ...

Millions of asteroids are floating around in space. Find out what you know about these relics of our solar system. (Jungmin Ryu for The Washington Post) Warning: This ...