Sunspots are strange shadows on the Sun’s surface and vary in size and groupings.
About 75 percent of sunspots come in groups of two or more, with one leading umbra, or center dark patch, that is usually the first to appear and the last to vanish.
The largest recorded group of sunspots was measured on April 8, 1947.
It covered some 11,300 square miles, or 18,000 square km, a little more territory than in the state of Maryland.
Some scientists propose that sunspot activity may effect weather on Earth.
During the Maunder Minimum, London’s Thames River froze over most winters, quite a rare occurrence In England’s temperate climate.
