Earth Day reaches it’s 40th anniversary. The annual celebration of our environment began in 1970. Here’s the top green stories and stunning images of earth from space…

NASA Celebrates Earth Day with photographs of planet Earth in an amazing slide show.

50 Green Tips for Earth Day on climate.weather.com

See human footprint from space on earthsky.org

40 years after the first Earth Day, the world is in greater peril than ever. While climate change is the greatest challenge of our time, it also presents the greatest opportunity; an unprecedented opportunity to build a healthy, prosperous, clean energy economy now and for the future. Visit earthday.org

Earth Day at 40: Our Changing View of the Planet on space.com

The Earth Observatory shares images, stories, and discoveries about climate and the environment that emerge from NASA research.

Whole-Earth Views from Geostationary Satellites at planetary.org