STEREO (Solar TErrestrial RElations Observatory) is the third mission in NASA's Solar Terrestrial Probes program (STP). This two-year mission will employ two nearly identical space-based observatories - one ahead of Earth in its orbit, the other trailing behind - to provide the first-ever stereoscopic measurements to study the Sun and the nature of its coronal mass ejections, or CMEs.
Click to View STEREO Science Images

By combining images taken almost simultaneously from the Ahead and Behind STEREO spacecraft, researchers have generated a 3-D sequence of four images that track an active solar region over about a one-week period (April 29 through May 5). These images can be viewed with red and cyan 3-D paper glasses. Credit: NASA/Johns Hopkins University Applied Physics Laboratory.
View NASA galleries  |  View STEREO galleries  | View JHU/APL galleries