Credit: SOHO (ESA & NASA)
These two images of the Sun were taken at nearly the same time on February 3, 2002. The image on the left shows the Sun in visible light. Several sunspots dot the face of the Sun. The image on the right shows the Sun in ultraviolet (UV) light at a wavelength of 30.4 nanometers (304 Ångstroms). The Sun's lower atmosphere (chromosphere) shows up especially well in this UV wavelength. Bright areas in the UV image reveal hot, magnetically disturbed regions in the chromosphere. Notice how these bright areas in the UV picture correspond to the locations of sunspots in the visible light photo. Sunspots are regions of powerful magnetic disturbances on the Sun's surface (photosphere) which in turn generate hot, high energy disruptions in the Sun's atmosphere. Solar flares and coronal mass ejections (CMEs) often erupt from these active regions around and above sunspots. These images were captured by NASA's Solar and Heliospheric Observatory (SOHO) satellite.