Earlier this week, NASA announced their STEREO project to map the entire sun in 3D. STEREO employs two orbiting satellites – “Ahead” and “Behind” – to map the surface of the sun in real-time. This is intended to provide early warnings in the event of solar flares and other such occurrences that tend to disrupt communications.
By combining images from NASA’s Solar Terrestrial Relations Observatory (STEREO) Ahead and Behind spacecraft, together with images from NASA’s Solar Dynamic Observatory (SDO) satellite, a complete map of the solar globe can be formed. Previous to the STEREO mission, astronomers could only see the side of the Sun facing Earth, and had little knowledge of what happened to solar features after they rotated out of view.
Following this, space.com posted an amazing image of a solar filament (shown here) that scientists estimate stretches across nearly 700,000 km of the sun’s surface.
This infographic shows how the STEREO system works (click the image to view it full size):
And this video demonstrates how the whole system works: