This past Sunday, July 2, at 9:14 p.m. (peninsular time in Spain), the NASA SDO solar observation satellite captured a large flare, launched into space by our star and in the direction of our planet. The phenomenon had been generated by a huge sunspot, equivalent in size to 7 Earths and called AR3354.
After 8 minutes, the radiation emitted by the flare, and mainly composed of X-rays and ultraviolet light, reached the Earth and disturbed the ionosphere, a zone of our atmosphere that is essential for the propagation of radio waves. The effects were especially noticeable in the western United States and in some areas of the Pacific and lasted for half an hour.
The flare was classified with category X.1. The letter X is reserved for the most powerful, and the number indicates the level of affectation that these events can cause (those of level 1 generate strong disturbances in radio signals, while those of degree 10 are considered extreme).
For centuries, it has been known that our star goes through minimums and maximums of activity in cycles of about 11 years. This activity is traditionally measured by the number of spots visible on the solar disk.
The complex behavior of the Sun’s magnetic field, the most intense in the Solar System and which surprisingly reverses its polarity in every 11-year cycle, is responsible for the appearance of spots on its photosphere (the equivalent of its surface), and is the cause of solar flares or also of the so-called coronal mass ejections (eruptions in which the Sun throws gigantic amounts of material into space, composed mainly of protons, electrons and helium nuclei). That is why the measurement of the number of solar macules is a good indication of the level of activity of the star king.
The current cycle of solar activity (the 25th, counted from the year 1755 when they began to be numbered) began with the minimum of December 2019, with the record of an average of only 1.8 monthly spots, and is now moving towards its maximum. , initially scheduled for July 2025.
But this past June there has been a surprising increase in sunspots, the most important in the last 21 years (with a total of 163.4 macules). This seems to indicate that, perhaps, the maximum of the current activity cycle could be brought forward, or that we are heading towards a more pronounced maximum than could be expected.
The emission into space of high-energy radiation generated by solar flares, and of particles launched at high speed by coronal mass ejections, represents a danger to life as we know it. Fortunately, our planet protects us with the combined work of the atmosphere (which filters the most energetic light) and the Earth’s magnetic field (which captures particles arriving from the Sun).
But our technology is especially sensitive to the effects of these phenomena. The so-called solar storms are the manifestation of these affectations, which can interfere with communications, damage satellites, electronic equipment and even electrical installations.
For these effects to occur, the flares and coronal mass ejections must be directed towards the Earth. As the volume of space is immense, the probability of this happening is very small, but it increases significantly at times of maximum solar activity, when the frequency of these phenomena increases.
Although throughout its history the Earth has been subjected to constant bombardment of radiation and particles from the Sun, it is now, in an increasingly technical world, when we are most vulnerable.
In the year 1859 the most intense solar storm ever recorded took place. Known as the Carrington event, after the astronomer who observed it, it knocked out telegraph communications to Europe and the United States and caused fires in some of the equipment. In addition, it generated spectacular auroras that could be seen even from North Africa. Currently, a similar storm could cause very serious effects on our technology.
In March 1989, another solar storm left large parts of Quebec, Canada, without power for hours. A similar thing happened in Sweden in November 2003.
And in July 2012 a huge coronal mass ejection missed Earth by a margin of just 9 days. It is estimated that the damage it would have caused to satellites and electronic equipment would have been so considerable that it could have taken between 4 and 10 years to recover from the damage.
