Scientists have revealed shock findings in the search to understand the Sun’s magnetic field.
The effect – a mystery that has troubled scientists for centuries – begins relatively close to the surface of our star, new research suggests.
Despite its importance to life on Earth and its relative proximity, much remains mysterious about the Sun. That includes its magnetic field, and where exactly it comes from.
Galileo documented sunspots on the star, which mark magnetic solar activity, as far back as 1612. Since then, he and the researchers that followed him have been puzzled by where exactly that magnetic solar field comes from.
Researchers had previously come to believe that it originated deep within the Sun, around 130,000 miles under its surface.
But the new study suggests this might be a gross overestimate. The magnetic field could begin just 20,000 miles down, according to a new study.
Researchers said the findings, published in the journal Nature, could help scientists more accurately forecast powerful solar storms that cause the Northern Lights to appear in the night skies.
These storms can also cause cause destruction – wrecking Earth-orbiting satellites, electricity grids and radio communications – so knowing when these events will occur can prepare countries worldwide for potential damage.
Daniel Lecoanet, an assistant professor at Northwestern University’s Department of Engineering Sciences and Applied Mathematics in the US, said: “Understanding the origin of the sun’s magnetic field has been an open question since Galileo and is important for predicting future solar activity, like flares that could hit the Earth.”
He added: “Although many aspects of solar dynamics remain shrouded in mystery, our work makes huge strides in cracking one of the oldest unsolved problems in theoretical physics and opens the way to better predictions of dangerous solar activity.”
The sunspots and flares that appear on the Sun’s surface are driven by its magnetic field, which is internally generated through a process called dynamo action.
To find out more, the researchers developed state-of-the-art models to simulate the solar magnetic field.
It showed that changes in the flow of the super-hot ionised gas (known as the plasma) within the Sun’s surface layers were enough to generate magnetic fields in the same regions.
In contrast, the researchers said, the changes in deeper layers produced less realistic solar fields, concentrated near the Sun’s poles rather than the equator.
The models were also able to demonstrate how sunspots are linked to the sun’s magnetic activity.
The researchers said the patterns seen in the simulations matched the locations and timescales of sunspots that have been have observed by astronomers since Galileo.
Keaton Burns, a research scientist in Massachusetts Institute of Technology’s Department of Mathematics in the US, said: “I think this result may be controversial.
“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.”
Additional reporting by agencies
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
