Viewing Sunspots

The redheaded Italian Galileo Galilei saw spots on the sun when he looked at it in 1610 through a small telescope. Until then, the sun had been considered to be a perfect body--Galileo's discovery of a spotted sun so irritated the clergy of his day that an inquisition was held and Galileo was trundled off and put under house arrest.

Thanks to a suggestion by Fairbanks reader Mr. James Raymond, you can check yourself to see if Galileo was correct. All you need is a pair of binoculars strapped to a camera tripod pointed at the sun and a white paper screen held behind the binoculars about 2 feet from the eyepiece. Be very careful in conducting this experiment not to look through the binoculars when they are pointed near or at the sun--this could cause severe eye damage. Focus the binoculars until a clean image of the sun forms on the screen and you will see the sunspots lined up along the sun's equator. If you look at the spots several days in a row, you will see them move as the sun spins on its axis, one revolution each 22 earth days.

Not since 1958, two 11-year solar cycles ago, have so many sunspots appeared on the sun. Each month during 1979 more than a hundred sunspots were observed; in October 188 were seen. It is possible that as many will be visible during some months of the 1980 peak sunspot year or we may learn that the cycle actually peaked in 1979, there being some uncertainty because the cycles are not always exactly eleven years long.