May 11, 2012 | 8
Space weather forecasters are keeping a close watch on a large collection of sunspots that could unleash blasts of energy or charged particles toward Earth in the coming days. Sunspot region 1476, the dark patch resembling the Hawaiian Islands in the photo at left, is located near the center of the sun’s face as seen from Earth but has yet to act out in any major way. Sunspots are concentrations of magnetic flux on the sun’s surface, which often give rise to eruptive phenomena such as solar flares (releases of radiation) or coronal mass ejections (great belches of plasma).
Earth-directed coronal mass ejections, or CMEs, can cause geomagnetic storms that disrupt satellite communications or fry electrical transformers and damage power grids. (They also produce lovely aurorae at latitudes well below the poles.) The most recent bulletin from the National Weather Service Space Weather Prediction Center (SWPC) forecast that Earth’s geomagnetic field was “expected to be at quiet to unsettled levels with a chance for active periods” from today through Sunday, May 13.
The sunspot region, notes the SWPC, “continues to dissipate its energy in relatively small bursts of modest flares and weak CMEs. That output belies its appearance—large sunspots and entangled magnetic fields. Forecasters are vigilant, watch here should things break loose.”