The surface of the Sun has electrically charged gases that generate areas of powerful magnetic fields. The Sun's magnetic field goes through a cycle, called the solar cycle.
The Sun's magnetic field completely flips every 11 years or so, this means the Sun's north and south poles switch places.
The beginning of a solar cycle is a solar minimum, or when the Sun has the least sunspots. The middle of the solar cycle is the solar maximum, or when the Sun has the most sunspots. As the cycle ends, it fades back to the solar minimum and then a new cycle begins.
The outermost part of the Sun's atmosphere is called the corona. It is usually hidden by the bright light of the Sun's surface and can be viewed during a total solar eclipse.
The corona is far from its surface, yet it is hundreds of times hotter than the Sun's surface.
SunspotsSunspots are areas that appear dark on the surface of the Sun, they appear dark because they are relatively cooler than other parts of the Sun's surface.
Sunspots are relatively cool because they form at areas where magnetic fields are particularly strong, strong magnetic fields keep some of the heat within the Sun from reaching the surface.
Solar FlaresThe tangling, crossing, and reorganization of magnetic field lines near the sunspots cause a sudden explosion of energy called a solar flare. Solar flares release a lot of radiation into space and sometimes accompanied by a Coronal mass ejection (CME).
Solar Flares are the most powerful explosions in our solar system, when they reach near Earth, they can trigger intense lights in the sky, called auroras. Particularly strong Solar Flares can also interfere in power utility grids, which at their worst can cause electricity shortages and power outages.