. An artistís conception of the Solar-Terrestrial Relations Observatory, or STEREO, in which two spacecraft will provide the images for a stereo reconstruction of Coronal Mass Ejections, or CMEs. One spacecraft will lead Earth in its orbit and one will be lagging. When simultaneous telescopic images form the two spacecraft are combined with data from observatories on the ground or in low Earth orbit, the buildup of magnetic energy, the lift off , and the trajectory of CMEs can be tracked in three dimensions. (Courtesy of Johns Hopkins, Applied Physics Laboratory).

Copyright 2010, Professor Kenneth R. Lang, Tufts University