This series presents views of the Sun from NASA’s Solar Dynamics Observatory (SDO). The SDO spacecraft was launched February 11, 2010, and began collecting data a few months later.

One interesting aspect of the Sun is its sunspots.  Sunspots are areas where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun.  Because of the strong magnetic field, the magnetic pressure increases while the surrounding atmospheric pressure decreases.  This in turn lowers the temperature relative to its surroundings because the concentrated magnetic field inhibits the flow of hot, new gas from the Sun's interior to the surface.

Sunspots tend to occur in pairs that have magnetic fields pointing in opposite directions.  A typical spot consists of a dark region called the umbra, surrounded by a lighter region known as the penumbra.   The sunspots appear relatively dark because the surrounding surface of the Sun (the photosphere) is about 10,000 degrees F., while the umbra is about 6,300 degrees F.  Sunspots are quite large as an average size is about the same size as the Earth.