A huge coronal hole on the sun rotated towards the Earth this week. Coronal holes produce strong solar wind gusts that carry solar particles out to the Earth’s magnetosphere and beyond. These holes appear to be darker in extreme ultraviolet light images (as in this photo, which combines three wavelengths of UV light) because less matter exists at the temperatures observed. It is likely that the coronal hole generates some auroral displays on Earth.
Budd, Ken. "Extensive Coronal Hole in the Sun." Suburbanspaceman.com. N.p., n.d.
Web. 15 June 2013. Image Credit to NASA
Web. 15 June 2013. Image Credit to NASA