On Saturday, a massive loop of plasma arced from the sun. The snakey thread expanded, pouring off the sun’s surface until it rocketed away and erupted into space.
Keith Strong, a solar physicist who has worked for Lockheed Martin and NASA, posted video of the eruption on X, the site that was previously known as Twitter.
“THE BIGGEST ERUPTION I HAVE EVER SEEN!” Strong put pen to paper. “Note that it covers more than half of the sun.”
The incident was also caught by NASA’s Solar Dynamics Observatory. The plasma arc accumulating, then erupting, near the center-right of the sun’s disc may be seen in the video clip below, which is a time-lapse lasting many hours.
This sort of eruption is known as a coronal mass ejection (CME) because it happens in the sun’s outer atmosphere, the corona. CMEs launch charged, super-hot plasma into space, and sometimes, as in this example, that plasma reaches Earth.
Forecasters at the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) announced that the CME would cause a geomagnetic storm — a powerful disturbance in the planet’s magnetic field that can disrupt radio communications, drag satellites out of orbit, and occasionally disable power grids.
On the plus side, these solar storms produce spectacular displays of the Northern Lights, or aurora borealis, visible in the center of the United States.
The CME from the huge filament outburst is expected to reach Earth on Monday evening, according to SWPC forecasts.
However, about 9 a.m. Eastern Time, NOAA space sensors detected a quick, dramatic shift in Earth’s geomagnetic field. The CME had already arrived, approximately 12 hours ahead of schedule.
What went wrong with the space-weather forecast?
NOAA relies on spacecraft to function as “buoys” to gather data on the stream of particles streaming from the sun toward Earth in order to estimate the arrival time and severity of solar storms. However, only one of those buoys is now in a useful location.
“For the next year or so, we only have one view of the sun.” It’s like playing tennis with one eye closed,” Matt Owens, a professor of space physics at the University of Reading, told Insider in an email.
“Making precise timing predictions is difficult due to the complex nature of space weather, as well as a limited number of space-based sensors,” SWPC spokesperson Bryan Brasher said via email.
The strength of the storm after it comes is the other component of the solar-storm forecast. According to Daniel Verscharen, an associate professor of space and climate physics at University College London, this is “very difficult” to anticipate.
“The direction of the magnetic field in the plasma cloud always determines this.” If it’s heading in the opposite direction of the Earth’s magnetic field, the geomagnetic storm intensifies,” he told Insider via email.
However, the SWPC’s intensity projection for this CME was correct. It anticipated a moderate G2 geomagnetic storm, with the possibility of a significant G3 storm. The storm that eventually formed was largely G2, with a G3 peak overnight.
More solar storms are surely coming
According to NASA, this was the latest in a sequence of 22 CMEs that happened in one week, with three of them aiming at Earth.
“The sun’s been very active this last week,” Owens remarked.
In truth, the sun’s activity has been increasing for years as it approaches a decadal high. The sun’s peak was anticipated to be in 2025, but it now appears to be around mid-2024.
As a result, we’ve been seeing more solar storms. This time, we were fortunate. Another structure on the sun, known as a coronal hole, is growing this week, bringing with it powerful solar winds. On a different day, the combination of these events may have resulted in an extremely powerful solar storm.
The best-case scenario is that impending storms cause spectacular aurorae to appear considerably further south than usual. This time, observers reported seeing the aurora in Montana, Missouri, Virginia, and the United Kingdom.
In the worst-case scenario, which is extremely unlikely, all of the variables align to deliver Earth a very rapid and very intense solar storm. This once-in-a-century event would be powerful enough to disrupt Earth’s geomagnetic fields and harm infrastructure such as electricity grids and satellites.
However, this week’s eruptions and coronal holes are “a little bit too slow and a little bit too spread out,” according to Owens.
“These are all the right ingredients for some serious space weather — multiple Earth-directed CMEs and some fast coronal hole wind — but they haven’t quite been combined in this instance to cause real concern,” Owens said, adding:
“There’s a good chance of some decent aurora over the next few nights.” But there should be no serious issues with electricity grids or other infrastructure.”
Source: Business Insider Africa