Some Experts Expect This Week’s Auroras to Be as Spectacular as the Ones We Saw Last Month. These Are Their Reasons

In May, there was intense solar activity resulting in visible auroras and some interference in radio transmissions.

Solar activity doesn’t stop. This heightened activity is expected to continue or even increase as the Sun reaches the peak of its 25th cycle. Experts anticipate more solar storms and auroras in the first days of June, though they possibly won't be as strong as those in May. They will still, however, be significant.

An intense month of May. On May 10, a powerful solar storm caused auroras to be visible at low latitudes, even reaching Puerto Rico and southern Europe. Throughout the week, we also observed intense solar flares.

The activity began with the appearance of a sunspot in the Sun’s Active Region 3664, which grew to 17 times the diameter of our planet.

From the Sun to the Earth's atmosphere. According to the National Oceanic and Atmospheric Administration (NOAA) and its Space Weather Prediction Center, sunspots are areas of the solar photosphere obscured by intense magnetic activity. This magnetism originates from the interior of the Sun, leaving these spots on its surface.

Due to their significant activity, sunspots are often linked to major solar events, such as flares, coronal mass ejections (CMEs), and radio bursts. These events can be so intense that they reach Earth, resulting in various phenomena like auroras and geomagnetic storms.

And what about June? The Sun completes one rotation around itself approximately every 24.5 Earth days (the Sun’s surface doesn’t rotate uniformly). If we take into account Earth’s transit, the synodic rotation period is about 27 days. This means that for a sunspot to “point” towards us twice, practically a whole month must pass.

As a matter of fact, the sunspots associated with the events of the first half of May will return to our planet this week.

In principle, the return of these sunspots isn’t a sure sign that we’re going to see auroras like those we witnessed last month. The reason is that these sunspots have likely been stabilizing during their transit through the hidden side of the Sun, and when they return to us, they may not generate as many problems.

Moving towards the peak. The sunspots that were prominent in May are now fading, but it’s expected that new ones will appear. The peak of solar activity for Cycle 25 of our star is predicted for this year. It’s anticipated to arrive earlier and be stronger than previously thought, but it doesn’t seem likely to surpass intense peaks like that of 2003.

Currently, there are 186 sunspots, and we haven’t observed a sunspot-free Sun since 2022. This isn’t unusual: During the previous solar peak from 2012 to 2015, there was only one day without visible sunspots on our star.

Image | NASA’s Goddard Space Flight Center/Scientific Visualization Studio

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