It’s official: The sun is a sphere.
On Feb. 6th, NASA‘s twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star—front and back.
“For the first time ever, we can watch solar activity in its full 3-dimensional glory,” says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.
“This is a big moment in solar physics,” says Vourlidas. “STEREO has revealed the sun as it really is–a sphere of hot plasma and intricately woven magnetic fields.”
Each STEREO probe photographs half of the star and beams the images to Earth. Researchers combine the two views to create a sphere. These aren’t just regular pictures, however. STEREO’s telescopes are tuned to four wavelengths of extreme ultraviolet radiation selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments. Nothing escapes their attention.
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An artist’s concept of STEREO surrounding the sun. Credit: NASA”With data like these, we can fly around the sun to see what’s happening over the horizon—without ever leaving our desks,” says STEREO program scientist Lika Guhathakurta at NASA headquarters. “I expect great advances in theoretical solar physics and space weather forecasting.”
Consider the following: In the past, an active sunspot could emerge on the far side of the sun completely hidden from Earth. Then, the sun’s rotation could turn that region toward our planet, spitting flares and clouds of plasma, with little warning.
http://www.nasa.gov/mission_pages/stereo/news/entire-sun.html
