NASA MARKS EARTH DAY

This May 23, 2006 NASA image obtained on Earth Day, April 22, 2009, shows a plume of ash from the Cleveland Volcano in Alaska made shortly after Expedition 13 astronaut Jeff Williams contacted the Alaska Volcano Observatory to report the activity. He took this photograph from the International Space Station. AFP PHOTO / NASA == RESTRICTED TO EDITORIAL USE / NO SALES / GETTY OUT ==