Closer Look: Solar Max is Coming in 2025

by | December 13, 2023, 12:15 PM | Earth Science, Stars & Nebulae

People in more northern and southern latitudes may have noticed that aurorae are getting more common than we’ve seen in recent years. This is thanks to our Sun’s habit of flipping its magnetic poles every eleven years. As the Sun’s magnetic field becomes quite chaotic at the mid-point of this transition, the Sun appears pockmarked with sunspots. These cooler splotches on the Sun’s surface mark where magnetic field lines arc through the surface. These spots generally come in pairs and groups, and each one has the potential to trigger some sort of an energetic event, like a solar flare. These events can send particles crashing through our solar system, and when they are aimed at Earth, they trigger the spectacular aurorae we see. These particle storms and related events are classified as space weather.

And the aurorae aren’t the only thing happening. Less visible to the casual observer, these events can also cause radio blackouts, damage satellites, and even take out the power grid. Since solar max only comes every eleven years, the effects we see each cycle can change as our technology changes. Researchers currently think solar max – the time when the sun is most active – will occur sometime in late 2024, and with this cycle, we will experience just what a good blast of solar radiation can do to the small sats and CanSats and other sats in low-earth orbit. 

If history is to be listened to, it’s only a matter of time before a solar event wreaks havoc on both satellites and our ground-based society.

Observing our Sun and watching for sunspots is one of the easiest things a researcher can do in astronomy. All it takes is a pinhole and a surface to project the Sun onto. If you want the best possible view, you can even project the Sun’s light through a telescope and onto a surface that isn’t your eye… unless you want to go blind, because looking at the Sun through a telescope is how you go blind. 

The earliest scientific recordings of sunspot numbers date back to 1610, just one year after Galileo made public his work using telescopes for astronomy. Since then, researchers around the world have been sketching out the locations and counting the number of sunspots. This more than 400-year record allowed researcher Max Waldmeier to discover that stronger solar cycles, with a steeper increase in the number of sunspots, will reach their peak faster than less spotty cycles.

In a new paper in the Monthly Notices of the Royal Astronomical Society, researchers Priyansh Jaswal, Chitradeep Saha and Dibyendu Nandy note that the rate the Sun’s magnetic field loses strength as it flips also correlates with how early or late peak will arrive. Their research predicts that solar cycle 25, our current cycle, will peak in late 2024 based on the rapid decrease in the magnetic field and increase in Sunspots. Similar predictions from NASA and NOAA show it may be a bit stronger than the last solar cycle but still potentially below average. 

From the Sun, I’ll happily take “below average” behavior. The historical record has more than a few examples of our Sun lashing out and wreaking havoc on our modern world. 

Most famously, in September 1859, scientists Richard Carrington and Richard Hodgson observed a solar flare for the first time. A while later, the impact of particles on Earth’s magnetic field generated a geomagnetic storm that generated nascent electricity in telegraph lines — currents that in some instances threw sparks and shocked telegraph operators. In some relay systems, operators were able to operate the telegraph system just using the solar storm-related current for several hours. It’s estimated that a similar storm hitting Earth today could create damage with a cost equivalent to several percent of the U.S. Gross Domestic Product. 

These kinds of storms aren’t entirely rare on the timescale of stars or even nations. 

In February 1872, another huge solar storm rocked the Earth’s magnetic field and generated wild currents in the telegraph wires. Aurorae were seen as close to the equator as Bombay and Khartoum. A May 1921 storm hit as the modern power grid was beginning to take shape, and this storm caused fires, blew fuses, and generally took down large sections of the power grid and telegraph network. Even undersea cables were affected. These three storms over just 62 years show our Sun can turn on us to the detriment of our technology.

While more recent storms have been less powerful, their damage has been far-reaching. Radio blackouts caused by a 1967 storm caused panic of possible nuclear war. In 1989, a solar storm took out the power grid of Quebec and interfered with the U.S. power grid. A small solar flare in 2022 even caused 40 SpaceX Starlinks to plunge back through the Earth’s atmosphere.

Still from a video of prominence eruption showing a blend of 304 and 171 angstrom light imaged by the Solar Dynamics Observatory’s AIA instrument. Credit: NASA’s Goddard Space Flight Center/SDO

And this last problem is perhaps the currently most worrisome.

In addition to everything else they do, Solar Storms also cause the Earth’s atmosphere to bloat out as it absorbs energy. The increased size of the atmosphere can create drag on low-orbiting satellites, and this drag will alter their orbits and potentially even de-orbit them. Exactly how a satellite will get moved around is almost impossible to calculate, as it depends on the shape and size of the satellite as well as the uneven changes to our atmosphere. As this is going on, satellites will keep orbiting but on not well-known trajectories. Like a crowd of bicycles suddenly encountering high wind and rough pavement, it’s possible for collisions to occur as a normally stable mission finds itself pushed into contact with another mission. 

And just like one bicyclist’s faltering can take out an entire crowd of bicycles, it’s possible that one satellite collision and its resulting debris field can take out an entire swath of Earth orbit. Which can take out more of Earth’s orbit. This can ultimately lead to the Kessler syndrome of runaway collisions and a swarm of debris that brokers no safe passage from Earth to the solar system beyond. 

Our planet has been lucky so far. In recent solar cycles, we’ve seen extremely powerful solar storms launch particles out toward other parts of our solar system. We’ve been kept safe by luck, and we hope to make our own luck in the future through advancements in solar weather prediction. Researchers are working hard to use data from missions like Solar Dynamic Orbiter and the space-based Solar & Heliospheric Observatory to predict solar flares and the much more powerful coronal mass ejections. We aren’t as good at predicting these storms as we are at predicting hurricanes, but progress is being made slowly. 

With our current solar cycle peaking most likely in late 2024, now is the time to consider any aurora-chasing trips you might want to make. I’ve been lucky enough to see solar aurorae several times in my life, and they are absolutely amazing to see, even with just your unaided eyeballs.

Glass igloos at the Kakslauttanen Arctic Resort, Finland. Courtesy:

And there are more than a few places in the world ready to take your money in exchange for the potential to see stunning views while surrounded by anything from posh to rugged accommodations. Staying in some kind of a large windowed room is on my bucket list to do someday. My personal “if I could” list includes the Kakslauttanen Arctic Resort in Finland with its glass igloos, the ION resort in Iceland with its glass-walled lounges, and the Borealis Basecamp outside Fairbanks, Alaska with its igloos with less glass and more showers. While I won’t be making a trip this solar max, I am saving my pennies for 2035, when the Sun flips back again, and we see another solar max. Aurorae are best seen near the September and March equinoxes but are possible any time of year. Just remember it needs to be dark, so avoid polar summers.