NASA recently wished a Happy Halloween to their fans on Instagram and Facebook with a photo of the sun looking like a cosmic jack-o’-lantern. NASA’s Solar Dynamics Observatory captured this ultraviolet image in October 2014, showing active regions on our home star.
The active regions in this image appear brighter because those are areas that emit more light and energy. They are markers of an intense and complex set of magnetic fields hovering in the sun’s atmosphere, the corona.
You can find more images as well as download hi-resolution versions of this image on NASA.