A mixed region of sunspots pointing almost directly at Earth has just given off a major solar flare, which could disrupt power grids and communications networks for the next few days.
from NASA Solar Dynamics Observatory (SDO) first detected the sunspot area designated AR3006 (“AR” stands for “active region”) several days ago; now the region is located near the center of the sun’s visible disk.
SDO images show that a point near the center of the region has the opposite magnetic polarity of the surrounding region, meaning its magnetic field lines point in the opposite direction to nearby field lines. This mismatch creates an unusual situation that can cause major disruptions, called “magnetic reconnections“, when areas of different polarity interact.
And now it looks like the interaction has happened. Satellites in Earth orbit have detected a radio burst indicating an X1.5 class flare erupted from AR3006 shortly before 9 a.m. ET (2 p.m. Universal Time) on Tuesday, May 10. Experts told Live Science that the resulting eruption is impressive, but not necessarily that unusual.
It is likely that the eruption also caused a coronal mass ejection (CME), launching a bead of plasma that could impact Earth in the next few days.
Related: A strange new type of solar wave defies physics
There are five classes of solar flare: A, B, C, M and X, according to NASA. Each is 10 times more powerful than the previous class, and they are followed by a number from 1 to 9 that indicates their strength within that class.
But there’s theoretically no limit to the strength of the largest X-class flares: the most powerful on record, as of 2003, outstripped sensors at a classification of X28.
Coronal mass ejection
Jan Janssens, a communications specialist at the Brussels Solar-Terrestrial Center of Excellence – which coordinates international efforts to monitor the sun – called the new solar flare “impressive”.
But “I’m a bit surprised by the strength of the flare, because it was all just small sunspots,” Janssens told Live Science in an email.
AR3006 is a relatively small patch of sunspots growing in the remnants of a decaying active region, but its structure of mixed polarities means it has a greater likelihood of breaking up and releasing masses of energy into the space, he said.
Solar physicist Dean Pesnell of NASA’s Goddard Space Flight Center, the Solar Dynamics Observatory project scientist, said mixed polarity in the AR 3006 region is not uncommon.
“It happens when twisted magnetic field lines flip beneath the surface before they erupt,” Pesnell told Live Science in an email, adding that solar flares also appear to be more common in regions with magnetic fields. so complex.
Tuesday’s solar flare also caused an explosion of radio waves which indicate that it was accompanied by a coronal mass ejection (CME) of super hot plasma from the sun.
CMEs typically emit billions of tons of stellar matter at speeds of hundreds of kilometers per second, according to the NOAA Space Weather Prediction Center.
If CME material from the latest eruption hits Earth in the next few days, it has the potential to disrupt power grids and communication networks, and damage satellites.
At the moment, the sunspot region is pointing almost directly towards us, Janssens noted, but any risk of disturbance from the CME will diminish over the next few days as AR3006 rotates towards the western edge of the Sun’s visible disk.
Pesnell explained that determining whether a CME would hit Earth was a “difficult and interesting calculation” that depends on the location and dynamics of the CME filament. While such events were “hints into the workings of the solar dynamo,” Pesnell said, “we only see the results of the dynamo, rather than the actual mechanism.”
“It’s like trying to understand the water cycle on Earth by only looking at cloud tops and not knowing the precipitation and oceans below,” he said.
Sunspots are caused by magnetic disturbances in the sun’s outer layer that expose the slightly cooler layer below. Even average sunspots are larger than Earth, and the largest can be several times larger.
Although sunspots and solar flares occur more frequently near the peaks of the 11-year solar activity cycle, they are actually the result of a longer 22-year cycle in the polarity of the sun’s magnetic fields.
The sun’s magnetic fields become entangled as it spins through space about once every 27 days, according to NASA. At the height of a solar cycle, about every 11 years, the solar fields become so tangled that the entire star abruptly reverses its magnetic polarity – the equivalent of Earth swapping its magnetic poles.
When this happens, sunspot activity decreases as the tangled magnetic fields unravel again, until the sun has almost no sunspots left at the lowest point in the solar activity cycle. .
But the cycle begins again when the sun’s magnetic fields begin to tangle again; and therefore it takes 22 years for the magnetic polarity of the sun to be the same as before.
Although it may seem that the sun has been very active for the past few months, Previously reported Live Science that its activity is about the same as during the last solar cycle, and even less than it was at this time in the two previous cycles.
Records of the solar activity cycle began in 1775, and we are currently in the ascending phase of solar cycle 25; it is expected to peak in late 2024 or early 2025.
Originally posted on Live Science.