The same physics that governs black holes operates in the sun's outer layers
For four centuries, the sun's dark, wandering spots have been observed but never fully explained — a mystery stretching from Galileo's telescope to modern satellites. Now, an international team using NASA supercomputers has traced the sun's magnetic engine not to its deep interior, as long assumed, but to a shallow layer just beneath its visible surface. In resolving this ancient question, the researchers uncovered something stranger still: the same physics governing plasma around black holes appears to govern the quiet outer skin of our own star, suggesting the universe writes its rules in fewer languages than we imagined.
- A 400-year-old gap in solar science has finally closed — the sun's magnetic field originates in its outer 10%, roughly 40,000 miles below the surface, overturning decades of theoretical consensus.
- Previous models placed the solar dynamo deep in the sun's churning interior, but those simulations produced sunspots at the poles — directly contradicting what Galileo and every instrument since has observed.
- The new surface-origin model, built on MIT researcher Keaton Burns's Dedalus computational framework, matches the real-world clustering of sunspots near the equator with striking accuracy.
- The practical stakes are high: a clearer map of the solar dynamo could sharpen predictions of solar flares and coronal mass ejections that threaten satellites, power grids, and global communications.
- The discovery's most unsettling detail is its cosmic echo — the same magnetorotational instability that drives plasma into black holes appears to be operating in the sun's comparatively serene outer layers.
For four hundred years, astronomers watched dark patches bloom and fade across the sun's face without understanding their true origin. Galileo documented them in the early 1600s. Modern satellites tracked them with precision. Yet the question of where the sun's magnetic field is born remained unanswered — until now.
An international research team using NASA supercomputers has located the source: the sun's outer layers, roughly 40,000 miles below the visible surface — just the outermost 10 percent of its vast interior. The finding overturns decades of theory that placed the solar dynamo deep within the sun's turbulent convection zone. Lead author Keaton Burns of MIT and his colleagues took a different approach, asking whether small disturbances near the surface could grow into the magnetic structures we actually observe. Using Burns's own Dedalus computational framework, they found that perturbations in the top 5 to 10 percent were sufficient to reproduce the observed sunspot patterns.
The practical implications are significant. Sunspots cluster near the equator rather than the poles — a pattern Galileo noted and modern instruments have confirmed. When the team modeled a deep-origin dynamo, simulations placed sunspots at the poles instead. The surface model matched reality, and a more accurate picture of the solar dynamo could improve predictions of solar flares and coronal mass ejections that threaten Earth's satellites, power grids, and communications infrastructure.
The discovery carries an unexpected cosmic dimension. The mechanism driving the sun's surface magnetic field mirrors the magnetorotational instability found in black hole accretion disks — the same physics governing plasma spiraling into one of the universe's most extreme environments appears to operate in the relatively calm outer skin of our own star. It is a humbling reminder that the universe often obeys the same rules across vastly different scales.
Burns acknowledged the finding may provoke debate within a field long focused on deep-dynamo models. Published in Nature on May 22, 2024, the research marks a fundamental shift in how scientists understand the sun's magnetic engine. The team plans to refine the model further, simulating individual sunspots and tracing their connection to the sun's 11-year cycle — slowly assembling, as collaborator Geoffrey Vasil described it, the many complex interacting parts of a giant cosmic clock.
For four hundred years, astronomers have watched dark patches bloom and fade across the sun's face without fully understanding where they came from. Galileo saw them through his telescope in the early 1600s. Modern satellites have tracked them with precision. Yet the fundamental question—where does the sun's magnetic field originate?—remained stubbornly unanswered until now.
A team of international researchers using NASA supercomputers has narrowed the mystery down to a specific region: the sun's outer layers, roughly 40,000 miles below the visible surface. This may sound impossibly deep, but the sun's radius stretches 433,000 miles. The magnetic field, it turns out, is generated in just the outer 10 percent of the sun's superheated interior. The finding overturns decades of theoretical work that placed the solar dynamo—the engine driving all magnetic activity—much deeper, in the turbulent convection zone where hot plasma rises and falls like an endless storm.
Keaton Burns, a research scientist at MIT and lead author of the work, explained the shift in thinking. Previous models assumed you needed the violent churning of the sun's deepest layers to generate a magnetic field. But Burns and his colleagues took a different approach. Rather than simulating plasma flows throughout the entire solar interior, they focused on whether small disturbances at the surface could, over time, grow into the magnetic structures astronomers actually observe. Using a framework called the Dedalus Project—developed by Burns himself—they ran calculations showing that perturbations in the top 5 to 10 percent of the sun were sufficient to produce the observed pattern of sunspots.
The implications are immediate and practical. Sunspots are cool, dark regions where magnetic field lines tangle and knot. They increase in number during the sun's 11-year cycle and cluster near the equator rather than the poles—a pattern Galileo documented and that modern instruments have confirmed. When the team modeled the dynamo originating from deeper regions, the simulations produced sunspots at the poles instead. The surface-origin model matched reality. This suggests that better understanding the shallow magnetic field could help scientists predict solar flares and coronal mass ejections, the violent eruptions that threaten Earth's satellites, power grids, and communications infrastructure.
But the discovery carries an unexpected twist. Burns and his colleagues noticed that the mechanism driving the sun's surface magnetic field bears a striking resemblance to physics operating around black holes. When plasma spirals into a black hole, it cannot fall straight in because of its angular momentum. Instead, it forms a flattened disk that gradually feeds the black hole, heated by friction to incandescent temperatures. This accretion disk is turbulent and unstable because material closer to the black hole's edge moves more slowly than material closer to the center—a phenomenon called magnetorotational instability.
The sun's outer layers appear to operate on the same principle. The same physics that governs the violent environment around a black hole seems to be at work in the relatively calm photosphere of our star. It is a humbling reminder that the universe often obeys the same rules at vastly different scales, from the surface of the sun to the edge of a black hole.
Burns acknowledged that the finding may provoke debate. "Most of the community has been focused on finding dynamo action deep in the sun," he said. "Now we're showing there's a different mechanism that seems to be a better match to observations." The research, published in Nature on May 22, 2024, represents a fundamental shift in how scientists think about the sun's magnetic engine. The team plans to continue refining the model, attempting to simulate individual sunspots and trace how they connect to the sun's broader 11-year cycle. Geoffrey Vasil, a collaborator at the University of Edinburgh, put it plainly: the solar dynamo is like a giant clock with many complex interacting parts, and researchers are only now beginning to understand which pieces matter and how they fit together.
Citas Notables
We show that isolated perturbations near the sun's surface, far from the deeper layers, can grow over time to potentially produce the magnetic structures we see.— Keaton Burns, MIT
Most of the community has been focused on finding dynamo action deep in the sun. Now we're showing there's a different mechanism that seems to be a better match to observations.— Keaton Burns, MIT
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter where the sun's magnetic field comes from? Isn't the sun just doing what it's always done?
Because prediction depends on understanding. If you don't know where the field originates, you can't forecast when it will erupt. Solar flares knock out satellites and power grids. Getting this wrong costs real money and real disruption.
So they've been looking in the wrong place for four hundred years?
Not wrong, exactly. They were looking deep, where the most violent turbulence happens. It made sense theoretically. But the sun doesn't work the way the theory said it should.
And now they're saying it's near the surface?
In the outer 10 percent of the interior. Close enough to the surface that small ripples can grow into the structures we see. The simulations finally matched what Galileo actually observed.
You mentioned black holes. How does that connection work?
The same instability that makes plasma spiral into a black hole appears to be operating in the sun's outer layers. It's the same physics at radically different scales. That's the strange part—and the beautiful part.
Does this change how we predict solar storms?
Eventually, yes. But first they have to finish mapping how the surface mechanism connects to the 11-year cycle. It's like finding the first gear in a clock. Now they need to see how it drives the rest.