Articles tagged "c9.9"

Steve McDonough CRW_3333_1315681608_med

Geomagnetic storm continues

New sunspot AR1295 is emerging over the sun's northeastern limb and crackling with solar flares. The strongest so far, a C9.9-category blast, did something remarkable. Click on the arrow to watch an extreme ultraviolet movie from NASA's Solar Dynamics

September 13, 2011