Active Sun artwork. Solar flares are seen leaping from the Sun's surface. These are loops of plasma (charged gas) which are ejected from the surface and follow magnetic field lines before hitting the surface again. Several sunspots (dark) are also seen on the Sun. These are cooler areas of gas caused by intense magnetic fields. They are a sign of an active Sun, and typically appear in bands just above or below the Solar equator. The Sun reaches its peak of activity every eleven years. The cycle is thought to be caused by interactions between different layers in the Sun as they rotate at different rates.