CORONAL HOLE

A dark croissant-shaped hole has opened up in the sun's atmosphere, and it is spewing a stream of solar wind into space. NASA's Solar Dynamics Observatory took this picture of the vast opening during the early hours of Jan. 30th: Researchers call this a "coronal hole." Solar rotation is turning the coronal hole toward Earth. The stream of solar wind pouring from it will swing around and hit our planet in early February, possibly sparking polar magnetic storms. High-latitude sky watchers should be alert for auroras between Feb. 2nd and 4th.

http://sdo.gsfc.nasa.gov/assets/img/latest/latest_4096_0193.jpg