About the STEREO Mission

Why the need for STEREO?

Coronal mass ejections (CMEs), are powerful eruptions that can blow up to 10 billion tons of the Sun's atmosphere into interplanetary space. Traveling away from the Sun at speeds of approximately one million mph (1.6 million kph), CMEs can create major disturbances in the interplanetary medium and trigger severe magnetic storms when they collide with Earth's magnetosphere.

Large geomagnetic storms directed towards Earth can damage and even destroy satellites, are extremely hazardous to Astronauts when outside of the protection of the Space Shuttle performing Extra Vehicular Activities (EVAs), and they have been known to cause electrical power outages.

CMEs: a Fundamental Science Challenge

Solar ejections are the most powerful drivers of the Sun-Earth connection. Yet despite their importance, scientists don't fully understand the origin and evolution of CMEs, nor their structure or extent in interplanetary space. STEREO's unique stereoscopic images of the structure of CMEs is enabling scientists to determine their fundamental nature and origin.

back