Solar Orbiter Captures First Ever Motion of Sun’s Polar Magnetic Field. The Sun follows a steady rhythm. Its magnetic activity increases and decreases in a repeating cycle that peaks about once every eleven years. This cycle is driven by two huge flows of hot plasma—one in each half of the Sun. Near the surface, these plasma flows carry magnetic field lines from the equator to the poles. Deep inside, the plasma moves back toward the equator, creating a large circular motion across each hemisphere. Scientists call this process the Sun’s “magnetic field conveyor belt.” However, many details of this process are still unclear, especially what happens near the Sun’s poles. From Earth, scientists can only see these polar regions from the side, so it’s hard to study their magnetic properties. Most spacecraft have had the same limited view. According to Dr. Sami Solanki from the Max Planck Institute for Solar System Research, “To fully understand the Sun’s magnetic cycle, we need to know what’s happening at the poles. The Solar Orbiter can finally help fill that gap.” Since February 2020, the European Space Agency’s Solar Orbiter has been orbiting the Sun in long, tilted paths. In March this year, it moved 17° above the plane where the planets orbit, giving it a better view of the Sun’s poles than ever before. Researchers analyzed data from two of the orbiter’s instruments — the Polarimetric and Helioseismic Imager (PHI) and the Extreme Ultraviolet Imager (EUI) — collected between March 16 and 24. These instruments measured how plasma moves and how magnetic fields behave on the Sun’s surface.
For the first time, scientists got a detailed look at the supergranulation pattern and the magnetic network near the Sun’s south pole. Supergranules are huge bubbles of hot plasma—two to three times the size of Earth—that cover the Sun’s surface. Their movement pushes magnetic field lines to the edges, forming a network of strong magnetic regions. Surprisingly, researchers found that the magnetic field near the poles drifts toward the poles at speeds of 10 to 20 meters per second, almost as fast as in regions closer to the equator. Earlier studies, taken from less favorable angles, suggested this movement was much slower. These new observations are crucial because they reveal how plasma and magnetic fields circulate globally inside the Sun. Dr. Lakshmi Pradeep Chitta, who led the study, said: “The supergranules at the poles act like markers that show, for the first time, the Sun’s eleven-year magnetic circulation.” Still, scientists don’t yet know whether the magnetic conveyor belt truly slows down near the poles. The current data only show a short part of the cycle. To confirm these findings, researchers will need longer and more frequent observations in the future.
