The Sun in STEREO

STEREO-B image of an active region on the Sun not visible from Earth

NASA’s STEREO mission – twin spacecraft orbiting the Sun, one ahead of Earth and the other behind – has reached a milestone in its mission today: both spacecraft are now in position to be able to view the entire Sun at the same time, giving scientists the ability to monitor solar activity on both sides! This is a big deal, because being able to see in effect the “back side” of the Sun allows us to better predict what type of space weather Earth will be experiencing once the Sun rotates to bring that side to face us.

Huge prominence seen by STEREO on April 13, 2010

Launched in October 2006, STEREO (Solar TErrestrial RElations Observatory) has provided 3D views of the Sun and structures in its corona, including powerful coronal mass ejections (CMEs) that spew billions of tons of charged particles out into space. When and if these particles come our way they can affect our atmosphere, as well as disrupt sensitive satellite and ground-based electronics and pose a real danger to any humans in orbit. It’s important that we have the ability to monitor such solar outbursts, and with STEREO we can now see potentially active regions even before they rotate around the Sun’s limb.

One recent discovery made with STEREO observations was that solar storms don’t always travel in a straight line outwards from the Sun. They can rise and fall, zig-zagging along the plane of the solar system depending on how the solar wind is affecting them. Knowing how these clouds of solar particles move is crucial to predicting how they could potentially affect Earth.

NASA released the 360º images from STEREO today (on Superbowl SUN-day.) To see the full view of the Sun and a description of the mission, check out the video below created by NASA’s Goddard Space Flight Center.

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(Can’t view the video above? Click here.)

“There are many fundamental puzzles underlying solar activity. By monitoring the whole sun, we can find missing pieces.”

– Angelos Vourlidas, member of STEREO team, Washington, D.C.

Image: NASA. Video: NASA Goddard Space Flight Center.

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