The Sun emits its largest X-class flare of the solar cycle as officials warn bursts from a massive sunspot are “not over yet.”

The giant solar explosions of energy and light are not over yet. Officials said Tuesday that the sun had just emitted another major solar flare – and that it is the strongest so far in the current solar cycle.

The latest eruption peaked just before 1 p.m. ET, NOAA’s Space Weather Prediction Center said, with a Class X rating of X8.7. Class The center said the flare was an R3 or “strong” flare, meaning it could have caused a wide-area high-frequency radio communications outage for about an hour on the sunny side of Earth. This may also have caused problems with low frequency navigation signals during the same period.

“Eruptions of this magnitude are not common,” the center said in its update, also posting on social media: “Region 3664 is not yet complete!”

The flare originated from sunspot 3664. This spot, combined with region 3663, constitutes a cluster “much larger than Earth,” NOAA said last week. And as of Thursday, 3664 was only “growing and increasing in magnetic complexity and has evolved into a higher threat of increased solar flare risk.”

Two other eruptions – classified as X1.7 and X1.2 – also erupted shortly before, although they are also not expected to be linked to major impacts on Earth.

Despite the intensity of the flare, officials said there are no concerns yet about a coronal mass ejection or a large burst of solar plasma and magnetic field. These CMEs are at the origin of geomagnetic storms like the rare extreme storm which happened this weekend, sending the northern Lights at latitudes much lower than normal and causing chaos for GPS systems that farmers depend on at the height of the planting season.

“Due to its location, any CME associated with this eruption will likely have no geomagnetic impact on Earth,” the Space Weather Prediction Center said.

Earth is currently in solar cycle 25, which began in 2020. The last cycle maintained an average duration of 11 years and was the weakest solar cycle in a century, the National Weather Service said. Although the current cycle is expected to be quite weak and similar to the previous one, NOAA officials noted “a steady increase in sunspot activity” from the start.

“While we don’t predict a particularly active Solar Cycle 25, violent solar flares can occur at any time,” Doug Biesecker, a solar physicist at NOAA’s Space Weather Prediction Center, said in 2020.