The Solar Cycle

sun · space weather · cycles · astronomy

An 11-year rhythm. The Sun's activity follows a predictable 11-year cycle called the Schwabe cycle. During this time, the Sun goes from calm to chaotic and back to calm again.

Sunspots appear and disappear. Sunspots are dark patches on the Sun's surface that come and go with the cycle. At solar maximum, there are many sunspots, but at solar minimum, there are very few.

Solar flares and explosions. When the Sun reaches its most active period, it sends out more solar flares and ejects more material into space. These outbursts happen much more often during solar maximum.

Earth feels the effects. The solar cycle changes the amount of radiation Earth receives and can affect our radio signals, power grids, and even create beautiful auroras in the sky.

Scientists track the pattern. Astronomers have been counting sunspots for hundreds of years and discovered this cycle by noticing the activity rises and falls in the same way over and over.