Today (Sept. 27), a moderate solar storm will hit Earth, potentially causing auroras in the sky to dance at lower latitudes than normal. According to the National Oceanic and Atmospheric Association, the Northern Lights could be visible tonight in the north United States, including New York and Wisconsin.
NOAA stated that the storm, which is composed of charged solar particles, could cause satellite disruptions as well as some "power grid fluctuations” at high latitudes (especially above the 55th parallel north), NOAA noted.
The storm will still be relatively weak and rank as a G2 storm on a 5-level scale, where G5 is most severe. According to NOAA, widespread power outages are only possible in category G4 storms or above.
Solar storms are common forms of space weather. They occur when coronal mass eruptions (CMEs), which come out of the sun's outermost atmospheric, slam into Earth’s magnetic shield. CMEs are enormous blobs of plasma (electrically-charged gases that make up all the stars in the universe) that escape the sun's atmosphere and soar through space at hundreds to thousands of miles a second. CMEs take about 15-18 hours to reach Earth from the sun, according to NOAA.
According to NOAA, up to four CMEs could be heading for Earth right now.
The strength of each CME determines what happens next. Benign storms like the one today will collide with Earth's magnetic shield and compress it slightly. The collision causes charged solar particles to skitter along the planet's magnetic fields towards the poles, bumping into atmospheric chemicals along the way. These charged solar particles emit energy as light and glow in amazing red, green, yellow, and blue colors. This is how auroras occur.
The auroras that result from storms are generally more visible at low latitudes, the stronger they are. The really powerful category G5 storms can do even more. The Carrington Event, a famous 1859 geomagnetic thunderstorm that disrupted Earth’s magnetosphere caused so much damage that telegraph wires were able to burst into flames. Another storm struck in March 1989 and blacked out Quebec, Canada for nine hours. It also caused power outages throughout North America.
According to NOAA predictions, tonight's storm will not be as severe as previous disasters. However, it will be one of the most significant. The solar maximum is the most active period of the sun's 11-year cycle. The maximum is when the sun's magnetic field (which controls CMEs and other weather) is at its strongest. This results in stronger solar storms.
NASA predicts that solar activity will gradually increase up to July 2025. At which point, it will slow down to approach a new minimum.
Original publication on Live Science
