A solar flare is like a shot from a giant cannon: it blasts a stream of charged particles into space. When that stream reaches Earth, the planet's magnetic field usually deflects it, but in polar regions, particles penetrate the atmosphere. There, they collide with air atoms and produce a burst of gamma radiation — which detectors catch.

On November 11, 2025, a class X flare erupted on the Sun, accompanied by a strong proton event. Gamma-ray detectors at stations in the Arctic and Antarctica simultaneously recorded this event for the first time. The instruments showed two peaks: the first, fast one arrived at 10:38 GMT, and the second, delayed one at 13:08. The first peak was visible even at low latitudes, where Earth's magnetic shield is stronger, while the second was only seen where the shield is weaker, i.e., closer to the poles.

Comparison with data from the GOES-18 satellite showed that the fast peak coincided with protons of energies above 150 MeV, while the delayed peak matched protons of 12–99 MeV. This difference arises because more energetic particles travel faster and penetrate deeper into Earth's magnetic field. The event was named GLE #77—the 77th ground-level enhancement from solar protons in recorded history.

Polar gamma-ray detectors proved sensitive to such storms and can be used alongside neutron monitors. These events are not dangerous for people on Earth, but they can affect satellites and radio communications, so it's important to keep an eye on them.