Three years ago, NASA launched the Solar Dynamics Observatory
on an Atlas rocket from Cape Canaveral. Since that time, the millions of images returned have given us an unprecedented understanding of the sun.
This image is a composite of 25 images spanning the period of April 16, 2012, to April 15 this year. It uses the Solar Dynamics Observatory's atmospheric imaging assembly at a wavelength of 171 angstroms to reveal the zones on the sun where active regions are most common during this part of the solar cycle.
One of three instruments on board, the atmospheric imaging assembly creates an image of the sun every 12 seconds in 10 different wavelengths, giving detailed analyses of the sun at different temperatures over time.
The observatory continues to send images of phenomena, like solar flares and coronal mass ejections, at a rate of 150Mbps.