NASA released the first global view of our sun, courtesy of a pair of space probes collectively called Solar TErrestrial RElations Observatory, or STEREO.
Launched in October 2006, the two probes left Earth together but then separated and headed for opposite sides of the solar orb.
On February 6, STEREO-A and STEREO-B finally reached opposition, when each spacecraft was aimed at a different hemisphere.
In this configuration, the two probes allowed scientists to simultaneously see both sides of the sun for the first time in human history.
“This is a big moment in solar physics,” STEREO team member Angelos Vourlidas, of the Naval Research Lab in Washington, D.C., said in a NASA statement.
“STEREO has revealed the sun as it really is—a sphere of hot plasma and intricately woven magnetic fields.”
The global view is a boon to scientists studying the sun’s magnetic activity, such as coronal mass ejections and solar flares, which can fire huge blasts of charged particles toward Earth.
Until now we’ve had to rely on observatories that can see only the side of the sun facing Earth. It takes the sun about 27 days to complete a full rotation on its axis, so when storms were forming on the far side, they’d have plenty of time to build up and take us by surprise.
“With this nice global model, we can now track solar storms heading toward other planets, too,” added STEREO program scientist Lika Guhathakurta. “This is important for NASA missions to Mercury, Mars, asteroids … you name it.”
In addition to the released images, NASA put together a nifty video that illustrates how the STEREO probes work, what they can teach us about the Earth-sun interaction, and what STEREO will get up to as the pair of probes continues to circle back around the sun over the next few years: