Sunspots are areas on the surface of the Sun where there is a concentration of magnetic flux. They appear dark because they are cooler then the surrounding area of the Sun. Johannes Fabricius first observed sunspots in 1611 and was the first to publish his results. There are records that the Chinese also observed sunspots before that time. You can read more here. http://www.nasa.gov/missi...ws/400yrs-spots.html