After a period of quiet on the surface of the sun, everything changed this week with the strongest solar flare of 2025 and coronal mass ejections that could spark Northern Lights in the coming nights.
What Just Happened On The Sun
On May 13 and May 14, NASA spotted X1.2 and X2.7 solar flares, the strongest since March 28 and 2025 so far. Solar flares are unpredictable and intense bursts of energy and electromagnetic radiation from the sun’s surface. X-class denotes the most intense flares, while the number provides more information about its strength, according to NASA. There were also two slightly weaker M-class solar flares, rated M5.3 and M4.7, on May 14.
Most of the activity is coming from a new sunspot called 4087, which has appeared on the left-hand side of the sun as we see it, according to Spaceweather.com.
Coronal Mass Ejections And Auroras
Solar flares don’t cause auroras but shortwave radio blackouts. Traveling at light speed, radiation from a solar flare takes minutes to reach Earth. In the wake of the X-class solar flares, brief blackouts were reported across the world.
It’s what can follow in the wake of a solar flare that aurora-hunters are interested in. Solar flares often spark what solar physicists call a coronal mass ejection, during which a cloud of super-charged particles leaves the solar surface and travels across the solar system, though at a much slower speed than the radiation from a solar flare. In the wake of May 14’s solar flare, a CME was spotted, but it’s traveling towards Mars, not Earth.
Northern Lights Forecast
The aurora borealis is notoriously difficult to predict. That’s because it’s very difficult to know whether a CME is Earth-bound and, if it is, exactly when it will arrive. After all, there are no satellites close to the sun to detect the speed of a CME. That data can only be collected when the CME’s effect on the solar wind — the stream of charged particles released from the sun that travels in all directions in the solar system — is measured by NOAA’s DSCOVR satellite, which orbits Earth. DSCOVR measures the solar wind’s speed and magnetic intensity, which is critical in calculating how it is about to change. Only then can an aurora display be accurately forecast by NOAA’s Space Weather Prediction Center, but there’s not much warning — just 30 minutes. The Northern Lights are a result of the solar wind interacting with Earth’s magnetic field.
The Return Of Solar Maximum?
The sun has a roughly 11-year cycle during which its magnetic activity crests and subsides. How active it is is measured by counting sunspots on its surface, dark patches that indicate complexity — and often produce solar flares and CMEs. NASA and NOAA’s Solar Cycle 25 Prediction Panel announced the arrival of solar maximum in October 2024, though the exact date won’t be obvious for a few years. Some solar maximum periods have a double peak, which we could now be approaching.
Even when the number of sunspots begins to decrease, big displays of aurora are possible. “This period of solar decline is marked by a decreasing number of sunspots, but not necessarily by fewer impacts, even after the solar maximum,” said Lisa Upton, co-chair of NASA and NOAA’s Solar Cycle 25 Prediction Panel. In fact, the declining phase of solar maximum can see extreme solar events.
Wishing you clear skies and wide eyes.
