What Are the Strange Swirls on the Sun? Scientists Explain Mysterious Plasma Structures

Strange spinning motions seen in the Sun’s thin, jet-like spicules may not be caused by individual plasma jets twisting like tiny tornadoes after all. A new study published in The Astrophysical Journal on August 31, 2026, suggests that these apparent swirls can emerge from huge, folded sheets of plasma that look like separate spinning structures when viewed from Earth.

The finding comes from a three-dimensional radiative magnetohydrodynamic simulation developed by researchers Sahel Dey, Piyali Chatterjee and Robertus Erdélyi. Their model recreated the Sun’s atmosphere from below the visible surface into the lower corona and showed how curtain-like plasma structures can produce the spinning, braiding and splitting patterns seen in observations.

The Sun’s “spinning jets” may be a trick of perspective

Solar spicules are narrow, rapidly moving structures that shoot upward from the chromosphere, the atmospheric layer just above the Sun’s visible surface. They can reach several million metres in height and move at tens of kilometres per second.

For years, scientists have debated why some groups of spicules appear to rotate sideways or wind around one another.

The new simulation offers a different explanation. Instead of assuming that every bright strand is an individual tube of plasma, the researchers found that the material can form broad, fluted sheets resembling a pleated curtain.

When these sheets fold, curl, and overlap, an observer looking from a particular direction can see only the brightest portions. Those bright sections can appear as separate strands that move across one another, creating the impression that the spicules are twisting.

In other words, the Sun may not be spinning thousands of tiny plasma straws. Some of the apparent rotation could come from the way a much larger plasma structure is arranged in three dimensions.

The researchers demonstrated this by calculating how the simulated plasma would appear when viewed along different lines of sight. The projected structures reproduced several features seen in actual observations, including apparent rotation, braiding, splitting and merging.

What is actually making the plasma rise?

The simulation also provides a picture of how these structures are launched.

The process begins with convection inside the Sun. Hot plasma rises and cooler material sinks, producing constant churning beneath the visible surface. These motions generate slow-moving magnetohydrodynamic waves that travel upward through the solar atmosphere.

Because the atmosphere becomes less dense with height, the waves grow stronger as they move upward. Eventually, they steepen into powerful shocks.

These shocks compress and heat the plasma and push it upward, helping create the rising spicule structures.

The simulated spicules had characteristics broadly comparable with observations, including lifetimes of about 5 to 10 minutes, apparent speeds of roughly 20 to 70 kilometres per second and heights of about 6 to 16 million metres.

But the important part comes after the plasma is launched. The dense material develops strong differences in density along the edges of the curtains, creating conditions that can generate vortices.

Two different forces can create the swirls

The researchers identified two types of vertically extended swirling structures, which they call coronal swirling conduits, or CoSCos.

The first type is mainly driven by magnetic tension. Magnetic field lines can become twisted and exert forces on the surrounding plasma, producing a rotating flow.

The second type develops near the edges of spicules through baroclinic effects. In simple terms, differences in pressure and density across the plasma do not line up perfectly, generating vorticity, or swirling motion.

These two mechanisms can interact with the curtain-like plasma and give spicules their observed rotational appearance.

The simulated CoSCos could extend from the chromosphere toward the lower corona. They had rotational speeds of about 2 to 20 kilometres per second and typical lifetimes of 20 to 120 seconds.

The researchers also found that rotation was particularly noticeable as spicules began falling back toward the Sun. With some of their upward-moving mass already drained away, the structures had less inertia, making them easier for surrounding vortical flows to move sideways and rotate.

Observations from Hinode and IRIS support the picture

The team compared the simulation with observations from two solar observatories.

Hinode’s Solar Optical Telescope provided observations of the solar limb from November 7, 2007, while NASA’s Interface Region Imaging Spectrograph, or IRIS, provided observations from October 19, 2016.

Both datasets contained groups of spicules showing transverse and rotational motions similar to those produced by the simulation.

However, the researchers also found an important difference. Observed spicule groups showed more extensive braiding and longer intervals between crossings than the simulated structures. This indicates that the real Sun may have longer-lived or more energetic swirling flows than those represented in the current model.

That means the simulation is not the final answer. Instead, it provides a possible physical explanation that future observations can test.

Why the strange swirls matter

The discovery could change how scientists estimate the amount of mass and energy that spicules transport into the Sun’s corona.

If what looks like a collection of separate jets is actually the visible part of a much larger plasma curtain, simply measuring the brightest strands could give an incomplete picture of how much material is present.

The researchers also found that the swirling structures can carry energy and momentum upward, potentially connecting activity in the chromosphere with processes occurring higher in the corona and solar wind.

The study therefore does more than explain why the Sun’s spicules appear to spin. It suggests that some of the most familiar small-scale structures in solar images may be projections of much larger three-dimensional structures that are difficult to see directly.

The authors emphasize that observations from a single viewing direction cannot conclusively determine whether spicules are truly tube-like or curtain-like. Simultaneous observations from different viewing angles, combined with higher-resolution simulations, will be needed to settle that question.