are the aurora borealis dangerous? Powerful geomagnetic storms in May and October caused intense displays of the northern lights across the United States, as far south as Arizona and Florida. May was possibly the strongest hundreds of years. What is happening?

There is a lot of scaremongering online about the sun’s activity when it reaches its (perfectly natural) solar maximum (an event that occurs once every 11 years), but rest assured, viewing the Northern Lights is perfectly safe for observers. They occur hundreds of kilometers high in the atmosphere and pose no threat to people below.

However, electrically charged particles produced during geomagnetic storms can damage infrastructure, and experts are increasingly concerned.

Northern Lights Alert: Solar Flares and Coronal Mass Ejections

Space weather is divided into two major events on the sun’s surface that can have consequences for Earth: solar flares and coronal mass ejections. Both are increasing this year because the sun is now at its solar maximum period.

Solar flares are powerful bursts of radiation that typically arise from sunspots on the sun’s surface and travel at the speed of light. If they head to Earth, they arrive in just over eight minutes and trigger a geomagnetic storm. Minor events regularly cause radio outages for boaters and shortwave radio users, which can lead to radio blackouts. “The large impact of a solar flare is usually on the order of a minute on GPS systems, which is generally not a big problem,” said Andy Gerrard of the Solar-Terrestrial Research Center at the New Jersey Institute of Technology, in a interview. “The pilots have backup means to land, take off and operate the aircraft.”

Coronal mass ejections are huge clouds of magnetic fields and plasma ejected into space at speeds of up to 3,000 kilometers (1,900 miles) per second. They usually follow a major solar flare. A CME can cause a geomagnetic storm if it heads toward Earth. It can change the shape of Earth’s magnetic field to create spectacular auroral displays. “A coronal mass ejection takes two or three days, so we have time to prepare, but it can easily miss Earth,” Gerrard said.

Infrastructure damage occurs when a solar flare or CME is particularly powerful. That happened last May, when a “halo CME” saw several CMEs arriving at Earth traveling at different speeds at the same time.

ForbesNorthern Lights Alert: Six Major Solar Storms Coming Soon, Expert SaysBy Jamie Carter

Northern Lights Alert: One Night in May

May’s G5 geomagnetic storm was not as strong as it could have been, but it had unexpected consequences. In addition to putting pressure on SpaceX’s Starlink broadband internet satellites, the increase in charged particles affected GPS satellites, compromising the accuracy of critical GPS navigation systems used in modern agriculture.

“GPS receivers work when a signal is received at regular intervals, much like the rhythm of a metronome, from an orbiting satellite.” saying Tim Marquis, senior product manager at John Deere. “During solar storms, that signal collides with a ‘fog’ of charged particles and can be lost. And the machines can’t know exactly where they are thanks to this interference.”

Tell NOAA Aurora – 30 minute forecast It is designed not to help aurora hunters but those who oversee infrastructure that needs protection.

May’s event may have been relatively powerful, but it was nothing compared to what could happen. Solar superstorms involving auroras across the planet are considered once-in-a-century events and, thankfully, have yet to occur in the modern era. The three major solar storms in human history occurred in quick succession (in 1859, 1872 and 1921), more than a century ago.

Northern Lights Alert: Carrington Event

The most intense solar storm was the so-called “Carrington Event” of September 2, 1859, when astronomer Richard C. Carrington observed an explosion of white light from the sun for about five minutes. It was the largest solar flare ever recorded, an X45, and subsequently produced global auroras. However, it caused few problems in pre-industrial society other than electric shocks to telegraph operators. “As far as we know, it was one of the largest storms to hit the Earth in the last 200 or 300 years,” Gerrard said. “There is news from the time that says that the aurora is almost a global phenomenon.”

In the past, a massive once-a-century solar storm could occur without incident, but a solar storm of similar intensity right now could have profound effects. The most compelling evidence is what happened in Quebec, Canada, in 1989, when a solar storm destroyed power grids. “Back then, the power grid was more vulnerable because it was more interconnected,” says Gerrard. “If one area failed, other networks would absorb that load.”

During that event, there was a buildup of grid current in the northeastern US that caused transformers to fail simply because the load was much greater than anticipated under normal circumstances. “Since 911, many networks, not just in the US but around the world, have fast disconnects, so if the load gets too high when going from one network to another, they will automatically disconnect,” Gerrard said. “You won’t have that exhaustion.”

Northern Lights Alert: What would happen now?

If there was a giant solar storm now, local networks would go down, but they would probably be fixed in a day or two. “Transformers, repair equipment and repair equipment can be brought in from other areas,” Gerrard said. However, that could be impossible during a repeat solar superstorm on the scale of the “Carrington Event.”

a study published by Lloyd’s of London and Atmospheric and Environmental Research in 2013 suggested that a massive solar storm of Carrington strength could cost $2.5 trillion and its effects would last more than a year. A significant event could even affect The Internet’s vast network of undersea cables..

“Not only an electrical network would be lost; you would lose power grids all over the world,” Gerrard said. “Where do we go up again? Where do we get spare parts? Where do we get the transformers? How do we repair the electrical grid? How do we fix transatlantic cables, communications, whatever?”

Are we ready for another Carrington event? “All countries are a little bit lost and unprepared for that kind of scenario,” Gerrard said. The probability of “the big one” occurring is low, but we know from the geological record that they are inevitable. “They are more frequent than a near-Earth asteroid,” Gerrard said. “There will be one in the next 200 years.”

Northern lights alert: the challenge for meteorologists

“It’s always a challenge for us because everyone loves the Northern Lights and the bigger the storm, the further south it is visible,” said Bill Murtagh, National Oceanic Program Coordinator. Space weather forecast from the Atmospheric Administration (NOAA), at a press conference in October.

The problem is that space weather forecasters have to rely on models for most of the CMEs’ two- or three-day journey from the Sun to Earth. How fast does the CME travel? Is it really heading to Earth? Forecasters have real-time data only once the CME hits NASA’s DSCOVR and ACE satellites about a million miles away orbiting Earth. They measure the speed and magnetic intensity of a CME, which is essential for calculating how the solar wind is about to change. Depending on the speed of the CME, the satellites give as little as 15 to 30 minutes’ warning of a significant space weather event and subsequent Northern Lights displays.

Murtagh knows that everyone gets excited about the auroras, but “at the same time, we can’t wait for these big displays because they threaten our critical infrastructure,” he said. “We always have to be careful what we wish for.”

Wishing you clear skies and wide eyes.