Prepare to be mesmerized by the celestial dance of the aurora borealis! A strong geomagnetic storm, classified as a G3-class event, is expected to grace Earth’s atmosphere on Monday, September 16th, according to the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center. This celestial spectacle could paint the skies with vibrant colors, potentially visible as far south as Oregon, Iowa, and Pennsylvania, with many states along the U.S.-Canada border likely to experience a breathtaking display. However, the nearly full Harvest Moon might make it slightly challenging to spot the auroras as vividly as on a truly dark night.
Geomagnetic storms occur when massive bursts of charged solar material, known as coronal mass ejections (CMEs), hurtle towards Earth at high speeds, colliding with our planet’s magnetic field. These energetic particles, guided by Earth’s magnetic field lines towards the North and South poles, interact with atmospheric molecules like oxygen and nitrogen, causing them to release energy in the form of colorful auroral light.
Scientists observed a substantial CME blasting out of the sun on Saturday, September 14th, closely following a powerful solar flare erupting from sunspot AR3825. This solar flare, categorized as an X4.5-class explosion – the most intense class possible – signaled a potential glancing blow from the CME to Earth.
The G3-class storm predicted to hit Earth today sits comfortably in the middle of NOAA’s five-level geomagnetic storm scale, ranging from G1 (minor) to G5 (extreme). Aside from the stunning midlatitude auroral display, G3 storms can also disrupt GPS systems, low-frequency radio communications, and certain satellite functions.
To witness the captivating auroral light show, venture as far away from artificial light sources as possible, using a dark sky map if needed. This will be especially important given tonight’s bright moon. Although visible to the naked eye, a smartphone camera can capture the ethereal beauty of the aurora with greater sensitivity.
Solar flares, CMEs, and powerful geomagnetic storms become more prevalent during solar maximum, the sun’s peak activity period in its 11-year cycle. While initially predicted to begin in 2025, some experts suspect we may already be experiencing this period of heightened solar activity.
In addition to solar maximum’s influence, auroral activity tends to increase in September near the autumnal equinox. This surge is attributed to Earth’s tilt relative to the sun. As Earth faces the sun side-on during the equinox (falling on Sunday, September 22nd this year), charged particles in the solar wind can more easily reach the poles, creating auroras along their path.
If you can’t find ideal dark skies for tonight’s celestial spectacle, don’t fret! There will be another chance to witness this breathtaking display later in the month.
