The sun’s outer atmosphere is far more complex than previously thought
Newly analyzed images could help solve mysteries about solar wind and the superhot corona
A CALM FACADE The outer corona of the sun appears smooth and calm. But freshly analyzed images from NASA’s STEREO spacecraft, which blocks out the sun (center) to bring the corona into view, shows unexpected texture.
NASA
NEW ORLEANS — Despite its smooth appearance, the sun’s wispy outer atmosphere is surprisingly full of knots, whorls and blobs.
Newly analyzed observations from NASA’s STEREO spacecraft show that the sun’s outer corona is just as complicated as the highly structured inner corona, solar physicists reported December 12 at the fall meeting of the American Geophysical Union. That previously unseen structure could help solve some of the sun’s biggest puzzles, including how the solar wind is born and why the corona is so much hotter than the solar surface.
The corona is made up of charged plasma, which roils in famous loops and fans that follow magnetic field lines emerging from the surface of the sun (SN Online: 8/17/17). At a
