Atists impression of the twin
						  STEREO satellites

The Heliospheric Imager for the NASA STEREO Mission

Part of the SECCHI Consortium


Artists impression of
					 STEREO's Lunar Swingby Despite the importance of coronal mass ejections (CMEs), scientists don't fully understand the origin and evolution of CMEs, nor their structure or extent in interplanetary space. STEREO's unique 3-D images of the structure of CMEs will enable scientists to determine their fundamental nature and origin.

The STEREO mission provides a totally new perspective on solar eruptions by imaging CMEs and background events from two observatories simultaneously. One observatory is "ahead" of the Earth in its orbit and the other, "behind". Just as the slight offset between your eyes provides you with 3D Image of the Sun depth perception, this placement allows the STEREO observatories to obtain 3-D images of the Sun.

When combined with data from observatories on the ground or in low-Earth orbit, STEREO's data will allow scientists to track the buildup and lift-off of magnetic energy from the Sun and the trajectory of Earth-bound CMEs in 3-D.