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SDO Sees Trio of Mid-Level Flares

The sun emitted three mid-level solar flares on July 22-23, 2016, the strongest peaking at 1:16 am EDT on July 23. The sun is currently in a period of low activity, moving toward what’s called solar minimum when there are few to no solar eruptions – so these flares were the first large ones observed since April. They are categorized as mid-strength flares, substantially less intense than the most powerful solar flares.

Credits: NASA’s Goddard Space Flight Center/Genna Duberstein
Download this video in HD formats from NASA Goddard’s Scientific Visualization Studio
SDO sees an M7.6 solar flare
NASA’s Solar Dynamics Observatory captured this image of an M7.6 solar flare – as seen in the bright flash on the right side of the sun – on July 23, 2016. This is one of three flares that erupted in close succession. This image shows extreme ultraviolet light that is normally invisible to our eyes, but is here colorized in red.
Credit: NASA

NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured images of the events. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.

To see how this event affected Earth, please visit NOAA’s Space Weather Prediction Center at, the U.S. government’s official source for space weather forecasts, alerts, watches and warnings.

These flares were classified as M-level flares. M-class flares are the category just below the most intense flares, X-class flares. The number provides more information about its strength. An M2 is twice as intense as an M1, an M3 is three times as intense, etc. 

Of these three flares: The first was an M5.0, which peaked at 10:11 pm EDT on July 22, 2016. The second — the strongest — was an M7.6, which peaked at 1:16 am EDT on July 23. The final was an M5.5, which peaked 15 minutes later at 1:31 am EDT.

Updates will be provided as needed.

Karen Fox
NASA Goddard Space Flight Center