Yesterday, the Space Weather Prediction Center issued a warning that our planet is experiencing a moderate geomagnetic storm that will continue for the next 24 hours. There’s no reason to panic as they are quite common, and people might even be lucky enough to view some great aurora while it's going on.
The storm is currently classified as a G2 by the National Oceanic and Atmospheric Administration (NOAA). These types can trigger voltage alarms in power units at high latitudes but they don’t tend to cause much damage.
These storms can also cause auroras to be seen as far south as Minneapolis, and the Aurora Forecast predicts a high chance of aurorae tonight, weather permitting. If the weather is bad, don’t worry. there are about 600 of these storms for every solar cycle, which lasts 11 years.
Geomagnetic storms are created by the interaction between our planet’s magnetic field and the deluge of particles produced by our star. The Sun is always losing particles in the solar wind, but every once in a while it will produce a sudden burst of very fast particles in an event called coronal mass ejection.
At first, the NOAA predicted that the storm will reach a G3 level, which could cause minor navigation problems to satellites, make the signal on GPS devices intermittent and might require voltage corrections on devices.
While a strong storm requires caution when it comes to electronic devices and satellites, there is no harm expected for biological organisms as the NOAA didn’t expect an increase in solar radiation.
Monitoring the space weather is not easy. It requires constant monitoring of our star and a clear understanding of the processes that happened there. The latter is still somewhat nebulous, but the former is possible thanks to several missions like SoHO, the Solar Dynamic Observatory and a pair of spacecraft called STEREO (although, currently, only one is working). All of these have allowed scientists to keep a close eye on the Sun.