Suitable for middle school students. From the National Solar Observatory at Sacramento Peak. Nearly 400 years ago Galileo looked at the bright Sun through a telescope. Needless to say, this ill-advised activity caused him to see spots and suffer from partial blindness. However, some of those spots were real.
Sunspots are dark areas on the sun's fiery surface.
They are cooler than their surroundings, but that doesn't mean they are cold. Compared to the size of the Sun, sunspots appear tiny, but many are larger than the Earth. In 1843, the amateur astronomer Heinrich Schwabe found that sunspots come and go in a predictable 11-year cycle. At the peak of the sunspot cycle there is lots of solar activity, including frequent solar flares and coronal mass ejections. Here on Earth we feel the effects of the solar maximum when geomagnetic storms cause power outages and interfere with satellites and radio communications.