A new study published in the journal Nature indicates that the most powerful solar storms can generate consequences for Earth much more significant than current predictions suggest. The research raises an alert about potential damage to communication systems, power grids, and satellites.
For years, the scientific community believed there was an established limit to Earth's reaction to intense solar events. However, this belief is being challenged by the new work. The authors suggest that this supposed 'ceiling' might be an artifact resulting from the methodology used to measure solar wind. If this hypothesis is true, the most extreme events could be drastically more severe than previously thought.
Solar storms occur when coronal mass ejections and solar flares release charged particles toward the planet. Under normal conditions, they result in auroras. However, in scenarios of greater intensity, they have the potential to affect vital technologies.
Although the Earth's magnetic field offers effective protection against much of the space weather effects, causing them to usually appear as small anomalies or beautiful auroras, there are extreme exceptions. Maria Walach, a researcher at the University of Lancaster and co-author of the study, commented on the topic.
To verify this possibility, the team analyzed over one million records collected by NASA spacecraft located in closer proximity to Earth. The findings demonstrated that electrical currents in the upper atmosphere continue to grow as the solar wind becomes more vigorous. This implies that the previously cited limit in past research may not exist.
Among the main findings highlighted are: the analysis of over one million measurements; the possibility that extreme solar storms are more intense than estimated; the vulnerability of systems such as GPS, radio, satellites, and power grids; and the risk of very rare events causing damage greater than currently predicted.
According to Walach, although these extreme cases are infrequent, the scarcity of available data is a limiting factor. She emphasized that only time will reveal what happens in an extreme event that occurs, for example, once every thousand years.
The research does not anticipate the imminent occurrence of a super solar storm, but it reinforces the need to revise currently employed models. Historical examples illustrate the risk: the Carrington Event in 1859 paralyzed global telegraph systems. In 1989, a storm caused a power grid failure in Quebec, Canada. Furthermore, the Halloween Storms of 2003 impacted radio, GPS, and satellite communications.
Currently, the Sun is in its solar maximum, a period within its approximately 11-year cycle characterized by an increase in the frequency of coronal mass ejections and solar flares. In May 2024, the strongest geomagnetic storm in over two decades shifted auroras to atypical areas in the United States and Europe, causing temporary interruptions in radio communications, GPS equipment, and some satellite operations.
Despite this recent episode, it remained well below the magnitude of the Carrington Event and the extreme storms postulated by the new study. If the new estimates are confirmed, understanding space weather behavior will be crucial to protecting an increasingly dependent infrastructure of power grids and satellites.
Solar storms, known for their ability to cause the aurora borealis, pose a serious threat to a significant portion of Earth's technological infrastructure. Depending on the intensity of these phenomena, they can affect electrical grids, satellites, radio communications, and international internet connections.
The risks are related to the interaction between particles and magnetic fields emanating from the Sun and the planet's magnetosphere. Although extreme events occur rarely, historical records show that they have previously caused power outages and failures in various technological systems, prompting experts to discuss the readiness of current infrastructure for large-scale events.
Solar storms are a consequence of a process called magnetic reconnection. During this process, the rotation of the Sun causes its magnetic fields to twist, accumulating enough energy for rupture and reorganization. At this moment, vast amounts of energy and plasma are ejected into space.
These phenomena are generally divided into three main categories: solar flares, radiation storms, and coronal mass ejections (CMEs). Each interacts differently with the Earth's atmosphere, potentially causing geomagnetic storms, radio communication disruptions, and changes in the planet's magnetic field.
The U.S. National Oceanic and Atmospheric Administration (NOAA) classifies such events on a scale from one to five. Most recorded solar storms fall into low levels, while extreme classifications are extremely rare during the 11-year solar cycle.
One of the most well-known examples was the 1989 event when a geomagnetic storm led to a power outage in the Quebec region of Canada. Approximately six million people were without power for nine hours, an event dubbed 'the day the sun brought darkness.'
Geomagnetically induced currents can cause overheating in transformers, relays, and sensors, as well as overload power lines. Since this equipment is expensive and complex to replace, the sequence of damage can significantly prolong the consequences of a major incident.
The risk is not evenly distributed across the planet; regions closer to the Earth's magnetic poles are prone to more intense disturbances. The vulnerability level of power grids also depends on the specific electrical resistivity of the soil.
The rise of artificial intelligence has added new concerns related to solar storms. Because data centers require high power availability, prolonged power outages can negatively affect one of the fastest-growing sectors.
Scott McIntosh, former deputy director of the National Center for Atmospheric Research, stated in an article published in Space News that AI leaders should be most concerned about these risks.
Satellites are also among the most susceptible devices. Although they are designed to withstand certain space conditions, intense solar events can damage electronic components and shorten their lifespan.
Russell DeHart, lead engineer at NASA's Goddard Space Flight Center, explains that high-energy particles can temporarily flip bits in onboard computers, causing glitches known as single event upsets. In such cases, secondary operations may be suspended until the issue is resolved.
Coronal mass ejections also heat and expand the Earth's atmosphere, increasing drag for low-orbit satellites. This change can lead to a decrease in altitude and speed, increasing the risk of collisions with other satellites or space debris, which requires fuel expenditure for maneuvers.
In 2022, a solar storm knocked 38 SpaceX internet satellites out of orbit. In October 2003, a series of solar events affected about half of the world's operational satellites and damaged air travel, radio and television broadcasts, GPS systems, and scientific missions.
Changes in the ionosphere caused by solar storms interfere with radio wave propagation. This endangers systems that rely on this medium for long-distance signal transmission, including maritime, aviation, rescue, and military communications.
GPS navigation systems can also suffer because they depend on precise satellite positioning. In 2024, a solar storm affected GPS-equipped tractors, leading to losses estimated at 500 million US dollars.
Traditional mobile phone services generally experience fewer direct interference issues, as they use frequencies least affected by atmospheric ionization. However, an extreme event could cause indirect consequences if the power grids supporting these communications fail.
Global internet infrastructure can also be affected by solar storms. A 2021 study by researcher Sangit Abdu Joti from UC Irvine indicates that a powerful coronal mass ejection is capable of disrupting parts of the submarine cables responsible for international data traffic.
The fiber optic cables themselves are not directly affected by geomagnetic currents. The problem lies with the electronic repeaters installed along the cables to boost the signal, which can be damaged by induced currents during geomagnetic storms.
According to NOAA, over 95% of international data traffic passes through these submarine cables. The study found that the longest connections, especially between the United States and Europe, are the most vulnerable.
Extreme events are rare but concern scientists. The strongest recorded geomagnetic storm occurred in 1859 and was named the Carrington Event. At that time, telegraph systems failed, and some even caught fire.
More recent research points to evidence of even larger past events, known as Miyake events. One of these, which occurred in 774 AD, could have been approximately 12 times more intense than the Carrington Event.
Although storms of this magnitude are considered very rare, estimates by the National Academy of Sciences suggest that a geomagnetic catastrophe could result in losses exceeding 2 trillion US dollars. A 2025 NOAA report concluded that solar activity forecasting systems still need improvement.
