How You Can Observe Sunspots
An article featured in Sky & Telescope magazine gives a step-by-step explanation of how to view sunspots safely in your backyard. If you have a telescope, you can outfit it with a special solar filter that will protect your eyes from solar radiation and keep it from damaging your telescope as well. You also can project the sun's image onto a white card or paper held a foot or two behind the eyepiece of a telescope or binoculars on a tripod. To protect your lenses, stop the telescope aperture down to two or three inches by cutting a round hole in a piece of cardboard and fitting it over the front of the tube. Aim the telescope at the sun without actually making eye contact by moving the tube until its shadow on the ground is smallest and watching for light to come blazing through the eyepiece onto the white card or paper [source: MacRobert].
Sunspots' Effect on Earth
Sunspots are connected with other solar events like flares and coronal mass ejections (CMEs). A solar flare is a sudden release of energy from the sun, while a CME actually shoots hot plasma from the sun into space. The precise mechanisms that trigger flares and CMEs are not yet known, but the bigger the group of sunspots, the more intense such solar weather tends to be. Flares and CMEs can send enormous amounts of energy and charged particles hurtling into collision with the Earth's atmosphere, where they can cause magnetic storms that disrupt or alter radio and cell phone communication and can wreak havoc with electrical grids. During the 1989 solar max, for example, a power surge triggered by solar energy damaged transformers that were part of the Hydro-Quebec power system. That surge left 6 million people in Canada and the northeastern U.S. without electricity for more than nine hours. Oddly, sunspot activity actually can help ham radio reception because the increased radiation causes the atmosphere to bend higher radio frequencies back toward Earth.
The increase in radiation that accompanies a solar flare is a theoretical health hazard to spacewalking astronauts, crew and passengers in high-flying aircraft, but there isn't any evidence that people have actually gotten sick from such exposure.
It's unclear if there's a link between solar weather and changes in the Earth's climate, because our planet's climate is influenced by so many other factors -- from volcanic eruptions to man-made emissions of greenhouse gases. The Maunder minimum in the 1600s and 1700s, when there was almost no sunspot activity, coincided with a period of cold temperatures and severe winters in Europe and North America. However, scientists haven't been able to determine if the two phenomena were actually related, though they think that a decrease in the sun's ultraviolet emissions may have triggered the change in climate.
UFO watchers and paranormal enthusiasts also see links between the unknown and increased sunspot activity, but there may be more of a correlation with the intensity of a person's belief in mystical phenomena.
Next, we'll explore how astronomers studied sunspots and developed theories about them.