In recent months, scientists have been surprised by an unexpected increase in solar activity, which has resulted in an increase in solar flares and coronal mass ejections, phenomena in which the Sun launches into space, and very directional, large flows of radiation (in the case of flares) and particles (mass ejections, mainly of electrons, protons and helium nuclei).
The arrival of these emissions on Earth can affect communications and even damage satellites and other equipment, such as power plants. These effects are collectively known as solar storms (or geomagnetic storms), and although solar flares and mass ejections from the Sun have always existed, it is now, in an increasingly technological world, that they can cause greatest damage.
Solar flares and coronal mass ejections are phenomena that are generated due to the constant activity of the Sun’s intense magnetic field, an activity that also gives rise to the well-known sunspots, dark regions that appear in the photosphere of the star (the equivalent to its surface).
In fact, flares usually occur near sunspots and are often followed by mass ejections. This relationship between the three events allows the count of spots on the Sun’s surface to be used as an indicator of the level of solar activity.
Since the 19th century, it has been known that the Sun’s activity varies in cycles of approximately 11 years. A cycle begins with a minimum of sunspots (and associated phenomena, such as flares and mass ejections), and activity progressively increases until reaching a maximum. From that moment on, the amount of sun spots begins to decrease until reaching a new minimum that marks the end of the cycle.
We are currently within solar cycle number 25 (the first was defined beginning in the year 1755), which began in December 2019. At that time, some organizations such as NASA or the National Oceanic and Atmospheric Administration of the United States United States (NOAA), discussed their forecasts for the new solar period, forecasts that indicated a relatively mild cycle (like the one that had just ended, the least intense of the last 100 years), with the maximum located in July 2025 and an expected monthly sunspot count of 115 at the time of maximum.
However, the number of sun spots reached 159 in July of this year and 115 last August. Everything indicates that we are at a level of solar activity unprecedented in the last 20 years and that the maximum of the current cycle could arrive next year, months in advance of the forecast.
The flows of radiation and particles from the Sun are capable of causing various effects upon their arrival on Earth. Specifically, high-energy light from solar flares (usually And, for their part, the particles from coronal mass ejections alter the planet’s magnetic field, which causes geomagnetic storms that have consequences on the operation of certain electronic equipment. The nicest side of these solar storms is the increase in the number and intensity of auroras.
To estimate the consequences of a geomagnetic storm, a scale that ranges from grade G1 to G5 is used. A G1-level storm can cause slight oscillations in the electrical supply network, while a G5-grade storm can collapse some of these networks, leaving transformers inoperative, and preventing high-frequency radio communications for days in certain areas of the country. planet.
In recent days, solar storms of up to level G3 (categorized as strong) have been recorded. Thus, on Saturday, September 16, an enormous filament detached from the Sun at the same time as a coronal mass ejection directed toward the Earth was generated. Some of the images of the Sun went viral on social networks.
Three days later, the Earth’s magnetic field was affected by the arrival of the particle flow, which caused the appearance of auroras in regions of northern Europe and the United States.
And this past Tuesday, early in the morning, some areas of Kenya experienced disruptions in radio communications when the stream of high-energy light generated by a solar flare arrived, about eight minutes after rising from the Sun. A few hours later, the damage was repeated in Indonesia due to another solar flare. In a single day, up to a total of 18 of these phenomena were recorded.
Just on September 5, the data collected by NASA’s Parker solar probe a year ago, when it encountered the gigantic cloud of particles emitted by a large coronal mass ejection, was published. For two days, the probe navigated through the intense flow of material, just 9.2 million kilometers away from the Sun, and measured speeds of up to 1,350 km/s in the particles.
The event was so intense that one of those responsible for the mission admitted that, if the solar mass ejection had been directed towards Earth, the consequences for our technology could have been colossal, generating a geomagnetic storm of a level similar to the largest ever recorded and known as the Carrington event.
This storm, which occurred in 1859, left the telegraph service between Europe and the United States inoperative for days, causing fires in some of the power plants and the northern lights that could be observed in numerous regions of the planet, even reaching close to the equator.
There are precedents in more recent times. For example, in March 1989 a solar storm left the Quebec region of Canada without electricity for nine hours. An impact that was repeated, in October 2003, in large areas of Sweden. And in July 2012, a large coronal mass ejection nearly hit our planet (it missed by just nine days). Its power was so intense that some experts estimated that, if a geomagnetic storm had been generated, the consequences would have been global, affecting satellites, communications and electronic equipment, and it would have taken between four and ten years to recover from the effects. .
Due to the growing importance of solar phenomena for our technology, there are various organizations that constantly monitor the Sun, through terrestrial instruments and also satellites, with the aim of generating forecasts and alerts.
For example, the National Oceanic and Atmospheric Agency (NOAA) of the United States manages the constellation of GOES-R satellites that, from Earth’s geostationary orbit, monitor meteorological and solar phenomena. For its part, NASA has, also in geostationary orbit, the SDO solar telescope, capable of capturing one image of the Sun per second in high definition and through different filters.
The European Space Agency (ESA) maintains a panel on the Internet in which the most relevant solar observations made by the various instruments that the European organization has dedicated to monitoring the behavior of the so-called space weather are centralized.
