Solar Maximum Summer

Sunspots, Solar Flares and Solar Cycle 25

June 30, 2025

by Eryn Barwinski, Education Coordinator, Imagination Station

This summer, the Sun’s showing us its wild side, giving us the biggest and best light shows in the solar system!

The Sun has hit the peak of its solar cycle, known as solar maximum, a time of intense magnetic activity. About every 11 years, the Sun’s magnetic field flips, swapping north and south poles and launching a new cycle. Earth’s magnetic poles flip, too, but only every ~300,000 years!

Astronomers have identified sunspots, dark patches linked to magnetic activity in the sun's atmosphere, since the 1600s using clever projection techniques. They recognized that the sun periodically went from having large and more frequent sunspots to having very few. By 1755, they began recording these patterns officially, starting with Solar Cycle 1. We're now in Solar Cycle 25! Each new cycle is marked by the emergence of new sunspot groups with opposite magnetic polarity compared to the previous cycle.

Sunspots, photo by Eryn Barwinski

Sunspots often lead to powerful eruptions called solar flares, and when these are strong enough, they can blast streams of charged particles into space called coronal mass ejections (CMEs). The CMEs are the largest explosions in our solar system and can erupt from sunspots that are several times larger than the diameter of the Earth. In May and June 2025, we saw some of the most powerful flares in years, including an X2.7 and X1.9 flare, disrupting radio signals and sparking geomagnetic storms.

These outbursts can even supercharge the auroras that are mostly present at Earth’s north and south poles, making them visible as far south as Ohio and Michigan!

While solar flares can’t harm us on the ground, they do interfere with GPS, aviation, communications, and even power grids. CMEs can heat Earth’s upper atmosphere, dragging satellites and shortening their lifespans.

The good news is: many agencies, including NASA (National Aeronautics and Space Administration) and NOAA (National Oceanic and Atmospheric Administration), are closely monitoring space weather to better predict and respond to solar storms during this active period. Be sure to keep an eye on the skies!