Music: Stella Maris courtesy of Moby Gratis. Information about the individual clips used in this video is available at: http://svs.gsfc.nasa.gov/vis/a010000/a011400/a011460/SDO_Year_4_Visuals_List.html The sun is always changing and NASA's Solar Dynamics Observatory is always watching. Launched on Feb. 11, 2010, SDO keeps a 24-hour eye on the entire disk of the sun, with a prime view of the grac
