Today is Earth Day, a day set aside for awarenesss and appreciation of the Earth's environment, and our roles within it - this year marking the 40th anniversary of Earth Day. As a way to help appreciate and observe our environment, I've collected 40 images below, each a glimpse into some aspect of the world around us, how it affects and sustains us, and how we affect it. Happy Earth Day everyone.
![Earth Day 2009](https://cdn-ak-scissors.b.st-hatena.com/image/square/4af76c69863267ca7fea62bc3bb1e63047856598/height=288;version=1;width=512/http%3A%2F%2Finapcache.boston.com%2Funiversal%2Fsite_graphics%2Fblogs%2Fbigpicture%2Farchive%2F106783.jpg)