Earth Day activities take place not just on April 22 but sometimes days, even weeks, before and after that. So the calendar covers the entire months of April and May.

Our institute is named for Gaylord Nelson, and he is often called the founder of Earth Day. After Sen. Nelson died last year, we considered other ways to carry on his legacy. One obvious way was to help sustain enthusiasm for Earth Day.

Everyone agreed that having one place to post and view Earth Day-related events in the area would help.

Knowledge empowers people with our most powerful tool: the ability to think and decide. There is no power for change greater than a child discovering what he or she cares about. (Speech about Global Warming read on the National Mall for the 40th anniversary of Earth Day, 2010)

We're going to enjoy another day on orbit and we'll see you on Earth tomorrow.

This event created a complete blackout of high-frequency communications on the day-lit side of Earth, which included the entire U.S. and basically anywhere the sun was shining at this time. Communications used by emergency services along the Gulf Coast may have experienced problems due to this flare. Low-frequency navigation systems may also have experienced a period of significant degradation.