Tag Archives: solar

The darker section at the top of the Sun in the above video is a coronal hole – part of the star’s atmosphere where its magnetic field bursts open and spurts streams of solar material out into space. It appears as a dark “hole” on the surface of the sun because the process makes its atmosphere cooler and less dense than those around it. The footage was captured between July 13-18 by Nasa’s Solar Dynamics Observatory, a five-year mission aimed at learning more about how “space weather” released by the sun affects astronauts, satellites, other planets and Earth itself. The coronal hole pictured last month is particularly large, measuring at least 400,000 miles across – more than the width of 50 Earths placed side by side. Although it looks dark and lifeless it was likely releasing fast solar wind, or streams of charged particles, at up to 500 miles per second. This is …