Last Sunday, November 5, Javier Caldera made it clear that he did not want to miss the show. This 21-year-old from Cáceres, who enjoys astrophotography, knew that It is very likely that the northern lights will be visible in Europe on this day.. And he kept a close eye on the problem to make sure he caught something.

“Around 19:30 a fairly high probability of auroras was reached in areas such as Ireland and I knew that they would become visible from here, although very faintly on the horizon. At that moment I made a decision and went to the family farm, free of light pollution, on the outskirts of Cáceres, where I always take my astronomical photographs,” says Caldera. And he did it. Northern Lights in Caceres. And the photo that proves it. .

Last Friday, December 3, Consuelo Cid Tortuero, coordinator of SeNMEs and the Space Meteorological Research Group, already foresaw that this would happen: “We observed the Sun and saw what looked like a solar mass ejection, and that there were many chances of it will reach Earth. We all left the office knowing that there would be a party on Sunday.and that we will enjoy the aurora like children with new toys on Twelfth Night.

The expert clarifies that although this is not a common case, it is not unique either. This year also saw more northern lights in Spain, although in many cases light pollution or sunlight prevents us from seeing them. As he explains, The further north we go, the more likely we are to meet them.. Although in general there are the same options from anywhere on the peninsula, and some are even registered in the Canary Islands.

But, despite the fact that this is a beautiful sight, it is not a fact that they are happening. “If there are auroras in the sky This means that changes are occurring in the electric fields in the sky and on the earth., and this has some risks. Spain will never have tourists coming in search of the auroras, but we may suffer from the negative effects of the sun’s activity. So it’s definitely bad news that auroras are happening in our country,” says Sid.

The “risks” you speak of are numerous. and varied. On Earth, GPS systems, ATMs, electrical systems, transportation, and power plants, among others, may stop working or operate incorrectly. Communications may be disrupted and pipes may be corroded. And passengers flying on planes near polar regions may be exposed to additional doses of radiation.

Negative effects of auroras

“Auroras are a wonderful part of solar storms. But then we have potential problems that could affect us, especially a society as technologically dependent as ours.” This is how Victor Manuel Sanchez, Doctor of Physics and Professor at the University of Extremadura, sums it up, explaining that there are already concrete examples of the negative impact of solar activity on our planet.

A famous case is the solar storm that hit Quebec, Canada in March 1989, causing power outages. As a result, the region was left without power for several hours and caused millions in damage. More than a hundred years earlier, in 1859, the most powerful solar storm in human history occurred, the Carrington Event, which affected the great technology of the time: the telegraph. But there are also more recent cases. In February 2022, Elon Musk launched 49 Starlink satellites and a solar storm destroyed 40 of them.

“And there is the curious case of solar physicists avoiding World War III,” Sanchez says. “In 1967 At the height of the Cold War, the US Army’s radars and communications equipment stopped working.. They thought it was a Soviet maneuver and were ready to strike back. Fortunately, the Americans had already started observing the Sun a little earlier and were able to see that the problem was caused by a solar storm,” he adds.

How do auroras occur?

“We can say that three products come from the Sun, in quotes. One is light that takes five minutes to reach the Earth. The other is relativistic particles, which arrive in 15 minutes. And there are particles that are produced when the solar mass is ejected, which This journey takes from one to three days and it is they that can cause auroras.”Sid says.

However, it is important to emphasize that This ejection of solar mass may never reach Earth and simply disappear into space. But if they finally make it to our planet, a spectacle is guaranteed. “When they enter the magnetosphere, which is the Earth’s magnetic field that acts as a kind of shield, these particles interact with molecules in the atmosphere, which become excited. When the molecules return to their fundamental state, they emit light. And that’s why the light of the northern lights appears,” summarizes Sanchez.

The expert clarifies that the first magnetic field lines are directed towards the Earth’s magnetic poles, which are not geographic poles, and that is why auroras usually occur in these regions. But the more powerful the solar mass ejection, the more likely it is that they can be seen at lower latitudes.. So we can say that auroras are “indirect manifestations of solar activity.” And although the current solar cycle is quite “weak”, when the peaks occur, we see more auroras from Earth.

Their color will depend on the atoms that excited the solar particles.. For example, greenish ones refer to oxygen, and purple ones refer to nitrogen. But not all of them are visible from any point. “In Spain we will never see a green aurora because the colors form at different altitudes in the atmosphere. This is why the aurora in Cáceres was red, and as it goes up it becomes greener,” explains Cid, who details that they have even been recorded as purple or white, although these are less common.

“Solar storms can happen at any time. But for position of the Earth relative to the Sun, two peaks of activity are observed in the number of auroras. One in September, when autumn begins, and the other in February, at the end of winter. And this is because at these two moments the Earth is a little closer to the poles of the Sun, from where solar particles fly away at the highest speed. At the equator of the sun, the magnetic field is more closed, and it is difficult for them to escape,” says Sanchez.

Hazard Mitigation

Taking all this into account, both experts emphasize the need to adapt to risk, which has been shown to be real. Sanchez explains this: “It’s not that the aurora will end our civilization or cause a mass extinction. But we must monitor solar activity and continue research to know when solar storms will occur and what they will be like in order to mitigate potential problems. Because there are many of them throughout the solar cycle.”

Sid, who has been researching the Sun and its effects on our planet for many years, believes we are ready. “You can predict whether a solar storm will reach Earth in enough time. And Spain in particular can do this. But I would like to tell politicians and companies to seize this opportunity. Because our research was carried out with public funds, and they had very good results. I would like to believe that Spanish society will take advantage of this, but I don’t know if it does.”, the expert concludes.