The sun has released an almost non-stop barrage of solar flares in the past 24 hours, including nine powerful M-class flares.
AR3311 is joined by another huge sunspot — AR3310 — which was responsible for the colossal solar flare on May 16 that caused widespread radio blackouts. The volatile pair are slowly rotating into view and will be directly facing us by the weekend.
Solar flares are caused when magnetic energy builds up in the sun's atmosphere and is released in an intense burst of electromagnetic radiation. They are categorized by size into lettered groups, with X-class being the most powerful. Then there are M-class flares that are 10 times smaller than X-class flares, then C-class, B-class and finally A-class flares which are too weak to significantly affect Earth.
Within each class, numbers from 1 to 10 (and beyond, for X-class flares) denote a flare's relative strength. The strongest flare in the last 24 hours clocked in at M5.3 at 8:40 p.m. ET on May 18 (00:40 GMT on May 19).
A series of shortwave radio blackouts have been triggered by the fusillade of flares, sending a strong pulse of X-rays and extreme ultraviolet radiation barrelling toward Earth. Traveling at the speed of light, the radiation reaches Earth in just over eight minutes and ionizes the upper layer of Earth's atmosphere — the thermosphere — triggering shortwave radio blackouts on the sun-lit portion of Earth at the time of impact.
Solar activity is on the rise as part of solar cycle 25, which scientists predict will peak in 2025. To find out if there is a solar flare today and to keep up with the latest space weather findings, visit the National Oceanic and Atmospheric Administration's Space Weather Prediction Center to see the most recent solar X-ray data from the agency's GOES weather satellites that perch over the eastern and western U.S.
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Daisy Dobrijevic joined Space.com in February 2022 having previously worked for our sister publication All About Space magazine as a staff writer. Before joining us, Daisy completed an editorial internship with the BBC Sky at Night Magazine and worked at the National Space Centre in Leicester, U.K., where she enjoyed communicating space science to the public. In 2021, Daisy completed a PhD in plant physiology and also holds a Master's in Environmental Science, she is currently based in Nottingham, U.K. Daisy is passionate about all things space, with a penchant for solar activity and space weather. She has a strong interest in astrotourism and loves nothing more than a good northern lights chase!