Space weather watchers have warned in recent weeks of strong eruptions on our star
In recent weeks, various space weather agencies have warned of intense flares or even gigantic solar flares . Without going any further, this Sunday a ” cannon of fire ” was reported that rose to 20,000 kilometers in height (although it was ten times longer) and that released powerful currents of magnetized solar wind that could reach Earth and create Auroras at unusual latitudes. A day later, the UK Meteorological Office confirmed a second outburst whose effects could be felt later this week.
All these phenomena, do they mean that our star is changing? “Actually, all this is normal,” explains Javier Rodríguez-Pacheco , Professor of Astronomy and Astrophysics at the University of Alcalá (UAH) and principal investigator of EPD, the acronym for the Energetic Particle Detector instrument (Detector de Particles Energéticas in its translation to Spanish) aboard the Solar Orbiter mission , which is approaching the Sun to closely ‘scrutinize’ our star and unravel some of its mysteries, including solar cycles. “We are going up in solar cycle activity, and as it goes up we expect more eruptions,” he adds.
Because stars are huge balls of extremely hot, electrically charged fluid. This electrical charge moves around, generating powerful magnetic fields. Every eleven years (or so), this magnetic field ‘flips’: the north and south poles swap positions. And, after another eleven years, they return to their place. Each one is a cycle and, also in each one, there is a solar maximum and minimum in which the activity of the star increases and decreases. Scientists can tell what phase the Sun is in because of the number of spots that can be seen on its surface.
“In the solar maximum -expected for 2025- the peak of the number of sunspots will occur, which is usually accompanied by greater activity of solar storms,” says Rodríguez-Pacheco. And, the greater the number of spots, the greater the probability of flares or coronal mass ejections , which cause solar storms and have consequences on the environment of the Solar System. “However, the most intense events, of particles and storms, do not usually take place at the maximum but after the maximum. It is as if the magnetic energy that is stored there takes a little longer to release. It is precisely at the end of the cycle when the most intense events are observed».
Because yes, the Sun’s eruptions send powerful ‘jets’ of matter and energy into space. On Earth, we most commonly feel this power through the Northern Lights, the colorful glows in the sky caused by the interaction of these charged particles sent out by our star and our atmosphere. It is common near the poles, since our magnetic field , a kind of natural ‘protective layer’ of our planet, is weaker at these points; however, with stronger solar storms, the magnetic field deforms even more, causing these auroras to be visible at points where they are not usual (in fact, auroras have even been collected in Madrid).
In the case of extreme events, damage could be caused to radio communications, to terrestrial electrical networks and even put satellites out of action (in fact, a few weeks ago, SpaceX reported that forty of its ‘satellite soldiers’ from Starlink were literally ‘fried’ by a solar storm). “Solar physics has been warning of these dangers, especially since the SOHO mission , and the authorities have taken note. For example, in the US, where their electrical networks are weaker than those that exist here in Spain.
A very intense cycle
The activity of the Sun has only been scientifically monitored since 1755, so until now humanity has only been able to attend 24 complete cycles. The 25th officially began in December 2019, NASA and the United States National Oceanic and Atmospheric Administration ( NOAA ) announced. The one that stayed behind left a ‘quiet’ period: the maximum number of sunspots was 116, compared to an average of 179.
However, a study led by experts from the US National Center for Atmospheric Research (NCAR) and published in the journal ‘ Solar Physics’ already predicted eleven more ‘moved’ years, with between 210 and 260 spots at the maximum, which would place him in the ranking of the most active ever observed. “However, we are seeing that the predictions have fallen short,” says the UAH astrophysicist, who explains that his team, at the beginning of the Solar Orbiter mission, enthusiastically received any ejection from the Sun, which could serve to make its instrument, EPD, collect data. “But now they happen more or less every week. In fact, at the end of March twice as many spots were counted as predicted by the model, being the highest number in the last seven years. Everything indicates that we are heading towards an intense cycle.”
Still, calm down. “You don’t have to be worried, but prepared. And that’s what science is for. We can’t control nature, but we can understand it, and missions like Solar Orbiter will help us refine the models and better understand what happens with these solar cycles, which we still don’t fully understand.’