A rather massive coronal hole was recently spotted on the Sun by NASA's Solar Dynamics Observatory. The region — the size of 50 Earths — is spewing material into space at tremendous speeds. It may look terrifying, but astronomers say it's nothing to worry about.
The coronal hole was imaged on October 10, 2015. The image above was taken in wavelengths of 193 angstroms, which falls outside the bounds of human vision (NASA/SDO)
NASA says that these holes are magnetically exposed areas that generate high-speed solar winds. These dark, low density regions of the corona — the sun's outermost atmosphere — contain little solar material, have lower temperatures, and thus appear much darker than their surroundings. Coronal holes are normal, appearing at different places and with more frequency at different times during the Sun's activity cycle.
In light of the phenomenon, the NOAA Space Weather Prediction Center forecast a G1-Minor storm from the 14th to 16th of October. This space storm is relatively harmless, though it could disrupt satellites communications and high-altitude radio transmissions. The coronal hole produced a geomagnetic storm near Earth that resulted in several nights of aurora.
[ NASA ]