NASA's Solar Dynamics Observatory has captured an image of the Sun that shows a huge coronal hole, a giant dark area on the star's upper half. Coronal holes are areas where the Sun's corona is darker, and colder, and has lower-density plasma than average because there is lower energy and gas levels. Their magnetic fields are different than those of the rest of the Sun.
Emergency of such coronal holes results in bursts of energy in the form of solar winds that cause geomagnetic storms that can disrupt power, navigation and radio communication on Earth.