On 7th October 2024, an active sunspot, AR 3842, fired an X2.1-class solar flare, causing temporary radio blackouts across parts of North and South America and over the Pacific Ocean. This event followed another powerful flare from the same sunspot just days earlier. On 3rd October, AR 3842 unleashed the strongest solar flare of Solar Cycle 25, an X9.05-class flare. The latest flare, recorded at 3:13 p.m. EDT, led to an increase in ultraviolet radiation, which disrupted shortwave radio communications.
Solar Flare Classifications Explained
Solar flares are classified from B-class, which is the weakest, to X-class, which represents the strongest flares. While the flare on 7th October wasn't as intense as the historic X9.05 from last week, it still produced significant effects, including radio interference. The most powerful solar flare ever recorded occurred in 2003 and was estimated to be an X45-class event.
Potential Impacts of Coronal Mass Ejection (CME)
The U.S. National Oceanic and Atmospheric Administration (NOAA)'s Space Weather Prediction Center confirmed that Monday's flare included a coronal mass ejection (CME), which is currently being analysed for potential impact on Earth. While CME events typically take a few days to reach our planet, they can cause geomagnetic storms that disrupt satellites, power grids, and GPS signals.
Monitoring Solar Activity for Future Risks
Earth-directed CMEs are of particular concern as they can result in more than just auroras in the mid-latitudes. Stronger solar activity could affect crucial technology systems. NOAA continues to monitor data from its solar observation satellites, and any potential risks to infrastructure will be assessed based on the strength and direction of the CME.
By keeping an eye on such solar events, scientists aim to better predict and mitigate any harmful effects on Earth's systems.
