A full-disk multiwavelength extreme ultraviolet image of the sun taken by SDO on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter (greater than 1 million Kelvin, or 1,799,540 F). Credit: NASA/Goddard/SDO AIA Team
As usual, hit the link up there for a larger version of the image and more information.
Update 5/3/10: I haven’t read the Bad Astronomer (see blogroll) in while and happened to yesterday only to find a post with this image and more explanation, plus another very cool image from the SDO.)