From a distance, the Sun appears tranquil, radiating brilliant light that nourishes all life on Earth. However, upon closer inspection, the Sun is a chaotic battlefield that astronomers have only begun to comprehend in the past year.
Andrew Gerrard, head of the department and director of the Solar-Terrestrial Research Center at the New Jersey Institute of Technology, noted: “We didn’t think the Sun would be this active during this specific cycle, but observations have shown the exact opposite.”
We are at the peak of the solar activity cycle
The solar cycle typically occurs every 11 years. During this period, solar activity fluctuates from a minimum to a maximum, with peak activity occurring in the middle of the cycle when the Sun’s magnetic field reverses.
The most recent solar cycle spanned from 2008 to 2019. Currently, we are in the midst of the current solar cycle, approaching peak magnetic activity.
The increased solar magnetic activity has intensified over the past few years to the extent that it has blocked energy from deep within the Sun, preventing it from reaching the surface. This results in cooler pockets on the Sun’s surface, manifesting as dark spots known as sunspots.
Sunspots are appearing more frequently.
Scientists like Gerrard can monitor the level of solar activity by counting sunspots, which have reached record-high levels in the past year.
Earlier this month, the National Oceanic and Atmospheric Administration (NOAA) reported that preliminary observations detected 299 sunspots, all occurring within a 24-hour period. This number marks the highest daily sunspot count in over 22 years.
Monitoring sunspots is crucial because they are the starting point for significant solar flares (classified as X-class) and massive eruptions known as coronal mass ejections. These eruptions can pose threats to Earth, causing radio blackouts and power grid failures, disrupting GPS navigation, and even triggering satellites to fall out of orbit.
Alex James, a solar physicist at University College London, explains that not all sunspots produce an eruption, and not all eruptions pose a threat, as the energy beams may not interact with Earth. However, learning to predict solar storms is essential as it can provide us with additional preparation time.
The Sun is more active than we think
X-class solar flares and coronal mass ejections are magnificent to behold. However, when they erupt, they launch streams of high-energy particles into space at thousands of kilometers per hour. If these particles sweep past Earth, they can interact with the planet’s magnetic field and upper atmosphere, causing geomagnetic storms.
Geomagnetic storms can create stunning displays of the Northern and Southern Lights. Recently, in the Northern Hemisphere, these colorful displays have appeared further south than usual, observable even in states like Texas and Colorado. This is attributed to increased solar activity.
However, Gerrard warns that these high-energy particles are like “viruses” that can create various disruptions to the high-frequency radio communications used by military, airlines, and GPS systems.
Since January, geomagnetic storms have caused radio blackouts across four continents: North America, South America, Europe, and Africa.
This can lead to unstable GPS operations and even power grid failures. It particularly impacts aviation operations, as aviation authorities will never allow aircraft to take off without ensuring radio and satellite communication.
Another concern involves spacecraft. Gerrard analyzed: “If there is a coronal mass ejection, and if that material reaches Earth, it will increase the density in the upper atmosphere. This will create more drag, and greater drag will pull spacecraft down.”
In February 2022, a geomagnetic storm contributed to 38 Starlink satellites falling from their original orbit to a lower transitional orbit. Scientists suspect that the lower orbit, combined with a geomagnetic storm, caused them to re-enter the atmosphere and burn up.
And last May, the most significant geomagnetic storm in two decades struck Earth, affecting Starlink services. Fortunately, no satellites fell out of orbit during that storm.
Solar energy activity is reaching its peak
Solar activity is expected to continue rising until it reaches a peak level, which scientists refer to as solar maximum.
James stated: “Current predictions suggest that solar maximum will occur in the latter half of 2025, but we will only truly know when the maximum happens after the activity begins to decline again.“
According to Mathew Owens, a professor of space physics at the University of Reading, although this cycle’s solar maximum is predicted to be stronger than initially expected by scientists, it is still average within a broader historical context.
However, James added that we are now more susceptible to the impacts of solar maximum than ever before due to our increasing dependence on satellite technology.