After an enormous solar flare erupted from the sun on Thursday, October 28, stargazers in northern parts of the United States may have caught a glimpse of an eerie glow stretching across the sky over the Halloween weekend, reports Tariq Malik for Space.com.
The aurora borealis, or northern lights, were visible in several countries, including Canada and Russia, report Paul P. Murphy and Holly Yan for CNN. The spectacle appeared when an X-class coronal mass ejection reached Earth over the weekend and created a G-3-class geomagnetic storm in its atmosphere.
The sun goes through periods of maximum and minimum solar activity when its magnetic field flips every eleven years. When the magnetic field flips, the sun’s north and south poles change places. Researchers count the number of solar spots to determine where the Sun is in its solar cycle when tracking the solar cycle. At the sun’s solar minimum, it will have the least number of sunspots, and at the solar maximum, the cycle is at its middle and will have the most sunspots. After the solar maximum, the cycle ends and will fade to a solar minimum, where a new cycle will begin. The most active solar activity occurs when the sun is in its maximum part of the cycle.
Powerful solar flares, or coronal mass ejections (CMEs), are part of the sun’s weather cycle. They occur when the sun’s magnetic field moves and plasma, or electrically charged gas, escapes the sun’s atmosphere and erupts into space at hundreds to thousands of miles per second, reports Brandon Specktor for Live Science. The current storm that passed last weekend traveled about 2.2 million miles per hour, Space.com reports.
CMEs usually take about 15 to 18 hours to reach Earth, and when they do, the charged gas will collide with Earth’s magnetic field, where charged particles flow down toward the North and South poles. From there, charged particles will collide with oxygen and nitrogen atoms, producing the famous glowing northern lights. Like the G3 category storm, stronger storms are powerful enough to move the aurora borealis further away from the North and South poles, making it visible in regions not normally seen, per a statement by the NOAA’s Space Weather Prediction Center.
The sun entered Solar Cycle 25 in 2020, and it’s predicted to reach its solar maximum in July 2025, per a statement by NASA. Because the sun is approaching the solar maximum, stronger solar storms are more likely to occur. Large solar flares can disrupt power systems and communications technology like GPS systems. For G3 category storms, issues with satellite navigation and low-frequency radio navigation may occur, Live Science reports.
In areas where the auroras are normally observed, many individuals took to social media to share spectacular photos of atmospheric phenomena. Areas further North had a greater chance to view the lights without travel and had better views than observers in lower latitudes of states in the Northeast, upper Midwest and as far west as Washington. Some parts of the northern U.S. also had rain, fog, or overcast skies that hindered views of the lights, CNN reports.