What would happen if Carrington-scale solar storm slams Earth? Transformers will melt and satellites will fall

Geomagnetic storms are a hidden risk Earth faces during solar maximum. Experts say that while scientists are aware that the Sun can unleash plasma and Coronal Mass Ejection (CME) on a large scale, what we don't know is how to prepare for them. David Wallace, an Assistant Clinical Professor of Electrical Engineering, warns in an article for ZME Science that the power grid and the internet infrastructure have not been tested against a major solar event, similar to the Carrington Event that slammed Earth in 1859. In May 2024, a G5 geomagnetic storm occurred. It was reported between May 10 and May 13, and is the most powerful geomagnetic storm to affect our planet since the 2003 Halloween storms. But this was nothing compared to the Carrington Event. Wallace examined how Earth will be affected if one day a similar solar storm occurs in the future.

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Can a Carrington-scale event happen in the future?

Scientists are sure that something like this can happen again, as CMEs are never going to stop during the lifetime of the Sun. Statistical modelling in a 2012 study shows that the probability of a same-scale storm hitting Earth is roughly 12 per cent per decade. Then, a study published in 2019 in Scientific Reports re-analysed historical geomagnetic data and lowered that risk, placing the odds at somewhere between 0.46% and 1.88% per decade. But NOAA and NASA scientists say that during the solar maximum, the short-term probability spikes to 2 to 12 per cent.

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In 2012, the Sun unleashed a massive CME that was physically similar to the 1859 Carrington Event. Earth was just lucky since it had moved out of its way, and the storm reached near our orbit nine days late. It slammed NASA’s STEREO-A spacecraft, which recorded the event.

If a Carrington-level event was to happen today and Earth took the direct hit, it would lead to a major upheaval and damage. Geomagnetically Induced Currents (GIC) will move through submarine and terrestrial cables, knocking out data centres. Satellites will be dragged as the Earth's atmosphere expands, causing them to slow down, and some could even fall out of orbit. Navigation systems will be hit, as disrupted GPS signals will affect commercial flights, national defence detection systems and even your smartwatch.

Currents exceeding 100 amperes can enter electricity grids, damaging high-voltage transformers internally. This has happened in the past with smaller-level solar storms, when the Hydro-Quebec grid collapsed, leaving 5 million people without power for nine hours. Also Read: Strongest solar storm radiation in over 20 years slams Earth: Where to see auroras?

How can damage from massive solar storm be prevented?

NOAA Space Weather Prediction Centre monitors solar activity. Even if it spots a major eruption from the Sun early, scientists would only have a few minutes to a few hours to take action. Wallace says we need to shield equipment like transformers with hardware. A total collapse can be avoided by developing "grid-load shedding" strategies.