Image of the far side of the Sun taken on February 2, 2011 when there was still a small gap between the STEREO Ahead and Behind data - the gap is now closed (Image: NASA)
On October 26, 2006, NASA launched two STEREO (Solar Terrestrial Relations Observatory) spacecraft. Using the Moon’s gravity for a gravitational slingshot, the two nearly identical spacecraft, STEREO-A and STEREO-B, split up with one pulling ahead of the Earth and the other gradually falling behind. It’s taken over four years but on February 6, 2011, the two spacecraft finally moved into position on opposite sides of the Sun, each looking down on a different hemisphere. The probes are now sending back images of the entire star, front and back, allowing scientists for the first time to view the Sun in 3D.
« Back to The Sun: now available in 3D