... The above movie shows how the Sun 's surface oozes during a single hour. The Sun's photosphere has thousands of bumps called granules and usually a few dark depressions called sunspots . ... Hot hydrogen gas rises in the bright center of a granule, and falls back into the Sun along a dark granule edge. The above movie and similar movies allows students and solar scientists to study how granules and sunspots evolve as well as how magnetic sunspot regions produce powerful solar flares . ...