Active regions are areas of enhanced magnetic activity on the Sun’s surface, generating the huge loops and dynamic surges observed here. Charged particles spinning along the field lines above the active region are illuminated in this wavelength of extreme ultraviolet light. The superimposed Earth icon gives a sense of just how large these loops are.
Fascinating picture of a coronal hole on the surface of the sun from October 2015. The coronal hole here is 50 times the size of the Earth!
The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to interplanetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged here on Oct. 10, 2015, by NASA’s Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze.