Seeing the whole sun front and back simultaneously will enable significant advances in space weather forecasting for Earth, and improve planning for future robotic or crewed spacecraft missions throughout the solar system.

These views are the result of observations by NASA's two Solar TErrestrial Relations Observatory (STEREO) spacecraft. The duo are on diametrically opposite sides of the sun, 180 degrees apart. One is ahead of Earth in its orbit, the other trailing behind.

Launched in October 2006, STEREO traces the flow of energy and matter from the sun to Earth. It also provides unique and revolutionary views of the sun-Earth system. The mission observed the sun in 3-D for the first time in 2007. In 2009, the twin spacecraft revealed the 3-D structure of coronal mass ejections which are violent eruptions of matter from the sun that can disrupt communications, navigation, satellites and power grids on Earth.

STEREO is the third mission in NASA's Solar Terrestrial Probes program within the agency's Science Mission Directorate in Washington. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the mission, instruments and science center.

The Johns Hopkins University Applied Physics Laboratory in Laurel, Md., designed and built the spacecraft and is responsible for mission operations.

The STEREO imaging and particle detecting instruments were designed and built by scientific institutions in the U.S., UK, France, Germany, Belgium, Netherlands and Switzerland.

To view the image with supporting visuals and information, visit: http://www.nasa.gov/stereo

Note: If no author is given, the source is cited instead.

• Sun
• NASA
• Astronomy

• Geomagnetic Storms
• Earth Science
• Geology

• Space observatory
• Phoenix (spacecraft)
• Solar flare
• Voyager program
• Compton Gamma Ray Observatory
• Geosynchronous orbit