The Sun is having a bad day, and the Earth has just been caught in a coronal mass ejection’s crosshairs. The solar outburst caused a minor geometric storm, according to the US National Oceanic and Atmospheric Administration (NOAA), with “disturbed circumstances” predicted to last for the next day or two. Large bursts of plasma and magnetic fields from the Sun’s corona are known as coronal mass ejections. They may be discharged in any direction, and some of them, like the one that happened on March 10, are blasted right towards our home planet.
Depending on its strength, the ensuing storm can cause varying degrees of disruption. The only visible consequence in most cases is an increase in the intensity of the aurora borealis and aurora australis, which may be seen from lower latitudes than usual. These aurorae are often only visible at high latitudes, around the north and south poles, and are caused by charged particles from the Sun colliding with the Earth’s magnetic field. When a coronal mass ejection happens, more of these particles reach our atmosphere, causing more ionization of molecules and a more spectacular light show.
A G2 level geometric storm slammed the Earth on March 13, according to the NOAA. This equates to a “moderate” storm, which is severe enough to disrupt high-altitude power systems and cause problems for spacecraft due to increased drag. During prior G2 level solar storms, aurorae have been seen as far south as New York. G5 geometric storms, for example, have been known to cause entire electrical networks to fail and aurorae to be seen all the way down to Florida.
While the current solar storm isn’t quite as powerful, it has caused the Northern Lights to appear in portions of the United Kingdom. The nighttime spectacle may persist in parts of Scotland for the next day or so, according to the UK Met Office, with more weak solar storms forecast until March 15. So far in 2022, our star has had more than its fair share of outbursts, and while life on Earth has been mostly unharmed, conditions in orbit have been quite turbulent. A geometric storm attacked hundreds of Starlink satellites immediately after launch last month, throwing them off track and forcing them to burn up in Earth’s atmosphere.
Our Sun goes through an 11-year cycle of activity, from minimum (least activity) to maximum (highest activity, including sunspots, flares, and storms) and back to minimum. Solar Cycle 25, the 25th since reliable records of solar activity began, began in December 2019 – indicating that we’re on track for a solar maximum in 2025. More occurrences like this are likely in the near future, with just three years before the next solar maximum, however whether the Sun delivers anything more dramatic than a G2 storm remains to be seen.