Severe Solar Storm Strikes Earth, Potentially Creating Global Auroras as Far South as California
A powerful solar storm struck Earth on Thursday, triggered by a coronal mass ejection (CME) that occurred on October 8. This G4-class geomagnetic storm is expected to create visible auroras as far south as California and Alabama, with the potential for severe disruptions to power grids and communication systems. NOAA warns that ongoing recovery efforts from Hurricanes Helene and Milton may be impacted due to the storm. There’s a possibility that the storm could escalate to G5-class conditions, akin to a notable solar event in May. The current solar maximum, a period of heightened solar activity, may be occurring earlier than initially predicted. Additionally, the CME may have affected comet C/2023 A3 (Tsuchinshan-ATLAS), which is currently making its closest approach to the sun in 80,000 years.
On Thursday, a significant solar eruption impacted Earth, instigating a “severe” G4-class geomagnetic storm. The National Oceanic and Atmospheric Administration (NOAA) forecasts that auroras may be visible as far south as California and Alabama.
The storm was triggered by a massive release of charged particles from the sun that occurred on October 8. This geomagnetic storm is expected to affect our planet’s atmosphere from Thursday evening into Friday, October 10-11, and could cause disruptions to power grids while producing brilliant auroras at much lower latitudes than usual.
According to NOAA’s Space Weather Prediction Center (SWPC), the northern lights may be visible across much of the northern half of the United States and could reach as far south as Alabama and northern California on Thursday night.
The storm could also complicate recovery efforts from Hurricanes Helene and Milton, putting additional stress on already weakened power grids and potentially disrupting communication systems reliant on low-Earth orbit satellites. SWPC representatives have communicated these concerns to relevant federal and state officials involved in hurricane recovery efforts.
As the geomagnetic storm unfolds, there is a possibility that it could escalate to “extreme” G5-class conditions, similar to the remarkable solar outburst in May that allowed auroras to be seen as far south as Florida. SWPC has committed to providing ongoing updates as the situation develops.
“Will this be a global phenomenon, or will it be confined to the United States, as was the case during the May storm?” asked Shawn Dahl, a service coordinator for SWPC, at a press conference on October 9. “It’s difficult to determine until we have a clearer reading. We would need to reach G5 levels for that to happen again, and there is a chance for that.”
The solar outburst, known as a coronal mass ejection (CME), was triggered by a powerful X 1.8-class solar flare that erupted on October 8. Solar flares occur when magnetic field lines on the sun violently realign, and they can be accompanied by CMEs—fast-moving blobs of plasma that can take several days to reach Earth if the planet is in the trajectory of the explosion. Upon impacting Earth, CMEs can cause significant disturbances in the magnetic field, leading to geomagnetic storms, technological disruptions, and widespread auroras. NOAA ranks geomagnetic storms on a scale from 1 to 5, where G1 storms are considered “mild” and G5 storms are classified as “extreme.”
Individuals can do little to mitigate the effects of the geomagnetic storm. However, aurora enthusiasts are encouraged to venture away from city lights for the best chances of witnessing the northern lights. No special equipment is needed to see auroras, but using a phone camera can enhance the colors that might otherwise appear faint to the naked eye.
Solar flares, CMEs, and auroras are more frequent during solar maximum, the peak of the sun’s roughly 11-year activity cycle. Although the current solar maximum was initially predicted to begin in 2025, some scientists believe it may already be occurring. Final assessments will only be possible once the maximum concludes and solar activity begins to wane.
Interestingly, another celestial body is also in the path of the CME: the bright comet C/2023 A3 (Tsuchinshan-ATLAS), which is nearing its closest approach to the sun in 80,000 years. There is a possibility that the comet’s tail was affected or even blown off by the solar eruption, reminiscent of earlier incidents involving other comets. Skywatchers will learn whether comet C/2023’s tail has survived once it re-emerges from the sun’s glare later this weekend.