The corona is the outer part of the Sun's atmosphere that can only be seen by Earth's inhabitants during a total solar eclipse. Because of the Sun's ever-changing magnetic field, its appearance is constantly evolving and different during each solar eclipse. But on April 8, according to a newly released simulation by Predictive Science, a San Francisco-based company that makes computer models of the Sun and whose work supports several NASA missions.
The simulation reveals a dramatic starburst-like pattern with several major highlights including the 7 o'clock bearing, 10 o'clock and 2 o'clock. Near the solar disk, some looping features are also visible.
Predictive Science has a history of making successful eclipse predictions. But predicting this eclipse will be more difficult than usual. That's because the current 11-year solar cycle is nearing its peak, or maximum, when the Sun's magnetic field is at its most chaotic.
The behavior of this magnetic field is important because it creates the plasma, or corona, of glowing superheated gas. This glowing plasma detects the Sun's magnetic field.
“The magnetic flux changes a lot on the Sun at solar maximum,” John Linker, head of predictive science, said in an interview. “It used to be done a month earlier [prediction] And then another prediction a week earlier. But now that the sun is so active, it's more challenging. This year we're doing something very ambitious, and that's a time-building model.
Despite the challenges of forecasting, NASA researcher Bob Lehman, who focuses on solar physics, said he expects this to be the most spectacular corona of its lifetime.
Corona is most impressive during eclipses, when the sun is at its minimum, when the sun is without sunspots for days or weeks. Sunspots are regions of enhanced magnetism on the Sun; The absence of sunspots means a negligible magnetic field and a simple corona. At the Sun's north and south poles, “polar streamers” of plasma follow magnetic field lines outward or inward, but lack many eddies, prominences, or significant features.
That's what happened during the total eclipse in Chile in 2019:
But with the solar maximum in mid-2024, scientists expect a more energetic corona.
“The more solar activity, the more spikes around the Sun,” Lehman said. “I think it would be really cool.”
On April 20 last year, a total solar eclipse of 1 minute and 2 seconds was observed for areas near Lermont. In the extreme north-west of Australia. Notice how much more powerful the corona is compared to the eclipse in 2019:
There are many more reasons why Corona on April 8th is so special. Two large sunspot clusters can transform the corona into even more spectacular shapes.
The reincarnation of AR3590 (AR stands for active region), is a sunspot cluster that produced high-profile X-class flares in late February. It can spin back into view from the far side of the Sun, creating prominences or large streamers and eddies of magnetism.
Beyond the highlights, there's a chance we'll catch a glimpse of a dramatic solar event called a coronal mass ejection, or CME. It is an explosive burst of plasma and magnetism from a sunspot. CMEs can interact with Earth's magnetic field and lead to auroras for our viewing pleasure (but they usually take at least a day or two to bombard our magnetic field).
“With flares and explosions, there's a very real chance we'll see a CME go from the side of the Sun,” Lehman said. “That would be absolutely fantastic.”
During an eclipse, ground-based observers will see only one phase of a CME every few minutes, as it breaks away from the Sun. The entire eruption lasts an hour or more, and can be seen along the path of totality by piecing together multiple images taken by people or scientific instruments.
“You can see a big bubble coming from the sun,” Linker said. “Even in the last couple of eclipses, I think there were small CMEs, and there are maps where people have drawn this bubble in the past.” Some of those maps date back to the 1870s.
If one starts before perfection, his time-generating model will capture it and predict its behavior—what he believes it will be.
Predictive Science plans to continue to update its predictions about the corona as more data becomes available leading up to the eclipse. They are Access here.
