The sun is currently experiencing heightened activity, marked by an increased presence of sunspots on its surface and the release of hot plasma into space. Sunspots are regions where the sun's magnetic field is particularly intense, capable of generating coronal mass ejections (CMEs), massive clouds of plasma expelled at high speeds.
Solar flares, intense bursts of electromagnetic radiation, also stem from the sun's magnetic field undergoing stress and twisting. These events are explained by Daniel Brown, an associate professor in astronomy at Nottingham Trent University, as consequences of magnetic field rearrangements. Solar flares, often accompanied by CMEs, produce immediate light and radiation that reach Earth in around 8 minutes, while the particles from a CME take a day or more to arrive, likened to a flash versus a cannonball in their impact.
In recent days, sunspot numbers have surged tenfold, accompanied by multiple daily CMEs. NASA's model predicts a potential collision between one of these CMEs and Earth by late November 25, pending further analysis.
When a CME interacts with Earth, it can induce a geomagnetic storm, disrupting our planet's magnetic field and atmosphere. Huw Morgan, head of the Solar Physics group at Aberystwyth University, explains that if a CME carries a magnetic field opposing Earth's, it leads to a more significant geomagnetic disturbance.
These storms vary in intensity, categorized by NOAA from minor (G1) to extreme (G5). The rarest and most severe are G5 storms, occurring approximately four times per 11-year solar cycle, while G1 storms are more frequent, numbering around 1700.
One notable effect of geomagnetic storms is the enhancement of the aurora, the colorful luminous display observed near the poles. Brett Carter, an associate professor in space science at RMIT University, clarifies that under normal conditions, charged particles in Earth's atmosphere generate auroras at the poles. During a geomagnetic storm, these particles penetrate deeper into the atmosphere, resulting in brighter and more expansive auroras. Depending on the storm's strength, the aurora may even be visible at lower latitudes than usual.
In essence, the recent surge in sunspot activity has led to frequent CMEs, one of which might impact Earth. This collision could provoke a geomagnetic storm, potentially enhancing the aurora and allowing for its visibility at lower latitudes.
