The Space Weather Prediction Center (SWPC), which is part of the National Oceanic And Atmospheric Administration (NOAA), has put out an alert about a minor geomagnetic storm hitting Earth on May 15, at 5pm EDT, and a moderate geo-storm hitting on May 16, stretching into the following day. This means celestial light shows known as auroras will be visible to northern latitudes, and may even be visible to northern parts of the United States.
The geomagnetic storms are the effect of electrically charged particles hitting and being captured by our planet’s magnetosphere. These particles are constantly being released by the Sun as “solar wind”, but intense solar activity can generate a “freak wave” of particles which do have some potentially dangerous effects.
The two storms that are about to hit Earth are the result of the plasma release from a series of three Coronal Mass Ejections (CMEs) that happened last week. CMEs are often seen in coronograph imagery as enormous arcs of material stretching far beyond the solar disk. The three CMEs appear to be associated with the disappearance of solar filaments, huge and twisting plasma structures in the Sun’s atmosphere.
The moderate geomagnetic storm is classified as a G 2. Power systems at high-latitude may experience voltage alarms and if it lasts for quite some time, such a storm could damage transformers. Geomagnetic storms can also affect satellites, which may require re-orientation by ground control. However, the thing that will intrigue people is the possibility of seeing the aurorae. Northern and Southern lights are likely to be visible to lower latitudes than usual. In the US, they could be seen as low as New York State, Michigan, and Idaho. In the Southern Hemisphere, New Zealand and Tasmania might see the celestial spectacle. The SWPC has a 30-minute aurora forecast for both hemispheres if you want to check your area.
While these two storms are nothing to panic about, it is important that we keep a watchful eye on the Sun. Powerful solar storms have the potential to be utterly catastrophic for humanity. The most powerful solar storm on record, the Carrington event, happened in 1859. It was responsible for aurorae from the poles to the tropics and it started fires in telegraph stations across the US and Europe due to the electric particles entering our atmosphere.
You can imagine how such an event would be even more damaging to today’s society. It is estimated that the cost would be in the order of trillions of dollars for the US alone.