Auroras likely as most active sunspot in years turns toward Earth

Update, Feb. 3 at 11 a.m. ET: The monster sunspot region 4366 is now facing Earth, and shows no signs of weakening. It is the most active sunspot of the current solar cycle (cycle 25). NOAA predicts that a glancing blow from a massive CME released toward Earth is likely this week. A minor (G1) geomagnetic storm is predicted to begin on Thursday (Feb. 5), with possible auroras at lower latitudes than usual. Stay tuned for more information.

A monster sunspot has taken aim at Earth after firing off dozens of powerful flares Sunday and Monday (Feb. 1-2) — including the most intense solar eruption in years.

Elevated geomagnetic activity — possibly resulting in vibrant northern lights at lower latitudes than usual — is likely on Thursday (Feb. 5), according to an alert from the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC). However, it's still too soon to know for certain.

The sunspot, called region 4366, appeared suddenly several days ago and has rapidly grown to roughly half the size of the infamous Carrington Event sunspot, which, in September 1859, fired a flare that triggered the most destructive geomagnetic storm in recorded history. This swift growth has left sunspot 4366 highly unstable; in a 24-hour period between Sunday and Monday, the region erupted with more than 20 solar flares, including at least 23 M-class flares and four X-class flares, the strongest category of solar flare, according to NASA.

This barrage of activity peaked Sunday around 6:57 pm EST, when the sunspot launched a strong X8.1 solar flare, according to the SWPC. This was the single strongest solar flare since October 2024, when the sun launched an X9.0 outburst.

The recent X-class flare immediately triggered partial radio blackouts in the South Pacific, according to Spaceweather.com, and fired a slower-moving blast of plasma called a coronal mass ejection (CME) in Earth's direction. The SWPC predicts that this CME will just miss Earth when it passes by on Feb. 5, but a glancing blow could be possible.

If the CME does clip our planet, charged solar particles will race toward Earth's magnetic poles, resulting in bright auroras.

The sun "wakes up"

Sunspots are vast, dark regions of magnetic instability that form in the sun's lower atmosphere. When the magnetic-field lines near these regions become too tangled, they may violently snap back into alignment, triggering solar flares and CMEs.

Sunspot activity peaks every 11 years, when the sun's magnetic poles flip places during a period called solar maximum. The frequency and intensity of solar flares and CMEs also peak during this turbulent time.

In 2024, NASA confirmed that solar maximum was well underway, with violent space weather likely to remain high through 2026. This could result in extremely rare and widespread auroral displays, like those observed in May 2024, when a monster CME pushed the northern lights as far south as Florida. The sunspot responsible for that storm lingered on the sun for more than three months, firing off nearly 1,000 solar flares in its lifetime, a recent study found.

Intense solar radiation storms can also have adverse consequences, such as radio blackouts, GPS disruptions, and damage to satellites and spacecraft.

The strongest solar flare of 2025 was an X5.1-class eruption recorded in November. Sunspot 4366 already has it beat — but whether it will hang on to break its own record remains to be seen.