# What is the cooler, darker area on the surface of the sun?

Sunspots are Storms in the lower atmosphere of the sun. They may be small as $16$ kilometers in diameter or as large as $160 , 000$ kilometers in diameter.
The number of sunspots that appear on the sun at any one time is always changing. But periods of very active sunspot activity seem to occur every $10$ to $11$ years. ***This activity has interfered with communication systems on the Earth.