Trick or treat? Massive solar storm could light up American skies this Halloween

An aurora may light up the dark skies over the US Northeast, upper Midwest, and could even stretch as far as the state of Washington, potentially giving skywatchers a rare treat this Halloween weekend.

The US National Oceanic and Atmospheric Administration issued a strong warning of an incoming geomagnetic storm on Friday.

“A G3 (Strong) geomagnetic storm watch is in effect for 30 – 31 October, 2021, following a significant solar flare and coronal mass ejection (CME) from the sun that occurred around 11:35 EDT on Oct. 28,” it said. “Analysis indicated the CME departed the Sun at a speed of 973 km/s and is forecast to arrive at Earth on 30 October, with effects likely continuing into 31 October.”

Aurora borealis occur when a flurry of charged particles interact with Earth’s magnetic field. The stream of particles comes from the solar wind, and strong gusts can be generated when the Sun releases plasma into space during a coronal mass ejection.

The best chance of seeing the colorful glow is to observe the sky at high altitudes, away from light pollution, provided you're in the right part of the world.

• How's this for a remote support fix? Solar storm early-warning satellite repaired with million-mile software update
• What could power an early-warning system for harmful radiation storms in Earth's Van Allen belts? AI? Let's see, say Los Alamos boffins
• 100 mysterious blinking lights in the night sky could be evidence of alien life... or something weird, say boffins
• Scientists stumped by strange X-rays from Uranus

The solar flare spewed from the Sun’s surface on 28 October was classified as an X1 event, meaning it was the weakest level of X, the most intense class of events. NASA said it disturbed some radio communications over South America and the polar regions.

An R3 (Strong radio blackout) event took place due to an X1 flare at 1535 UTC (11:35 am EDT) on 28 October from Region 2887. Initial analysis showed possible CME related signatures, however, analysis is on-going. Please follow our website for the latest information and updates. pic.twitter.com/44WJuqXQdM

— NOAA Space Weather (@NWSSWPC) October 28, 2021

The geomagnetic storm probably won’t affect electronics too much when it hits on Saturday. It’s possible it may cause some voltage irregularities and set off false alarms in some devices, and temporarily impact some radio and navigation systems, according to the NOAA.