If there were a solar storm as strong as the Carrington event of 1859, would it knock out the electronics in planes so they couldn鈥檛 land safely?
Mike Follows
Sutton Coldfield, West Midlands, UK
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The sun emits solar wind and occasional solar flares, followed by coronal mass ejections (CMEs), which release clouds of up to a billion tonnes of charged particles into space. While most CMEs miss Earth, those coming our way typically take one to five days to reach us. Our magnetosphere deflects most of the particles, and the atmosphere protects us from ionising radiation, but CMEs can cause geomagnetic storms.
Because the CME is a moving cloud of charged particles, it has an associated magnetic field that interacts with Earth鈥檚 field, causing it to vibrate. The changing field induces voltages, which drive geomagnetically induced currents along paths of least resistance on Earth鈥檚 surface, including power grids. A notable example is the 9 March 1989 Hydro-Qu茅bec power grid failure, which left over 6 million people without power for 9 hours.
The Carrington event of 1859, a significant geomagnetic storm, was caused by a CME that took 17.6 hours to reach Earth. Today, given a similar warning time ahead of an approaching CME, passenger jets could avoid the poles, where charged particles are most intense, or fly at lower altitudes to reduce radiation exposure. Aircraft could also be grounded if necessary. These measures would be to protect the passengers and crew.
That said, while electrical grids are vulnerable to geomagnetic storms, aircraft are less affected. Their smaller size means that smaller voltages are induced. Modern avionics are tested and protected against electromagnetic interference. Redundancy is built into these systems and, if necessary, a mechanical fail-safe could be deployed.
However, solar activity can affect aircraft navigation, so flights relying on GPS may be compromised by unreliable vertical guidance. High-frequency radio communication can also be disrupted by upper-atmospheric disturbances from solar storms.
Researchers warn of rarer, more powerful 鈥渟uperflares鈥�, or Miyake events, which could release energy up to 1000 times greater than the Carrington event. These could disrupt GPS by damaging or displacing satellites, and they would probably cause widespread power grid failures, bring down the internet and potentially pose an existential threat to humanity.
While electrical grids are vulnerable to geomagnetic storms, aircraft are less affected, as they are smaller
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