NASA is taking part in the celebration of Earth Day's 42nd anniversary on the National Mall in Washington, D.C., from April 20 through April 22, 2012.
NASA is taking part in the celebration of Earth Day's 42nd anniversary on the National Mall in Washington, D.C., from April 20 through April 22, 2012.
NASA's "Beautiful Earth" educational program combines interactive talks and hands-on workshops for students with live music.
In honor of Earth Day a half century into the space age, here is a list of the top 10 most requested Earth images taken by astronauts.