This week, the joint ESA/NASA Solar Orbiter spacecraft made a remarkable discovery. SOHO allowed scientists to observe in real-time the sun’s polar magnetic field as it moved in space. This revelation marks a significant breakthrough in solar energy research. It’s making first-of-their-kind discoveries on how the magnetic field is behaving, revelations that Earth’s observations have been unable to find.
Since its launch in February 2020, ESA’s Solar Orbiter has been traveling in elongated elliptical orbits around the sun, allowing scientists to gather unprecedented data. In March, the spacecraft ventured beyond the plane where most planets and space probes orbit the sun, achieving a tilt of 17 degrees that now enables a clearer view of the sun’s poles.
Solar Orbiter’s findings reveal a refined image of the supergranulation and magnetic network at the sun’s south pole for the first time. Now the spacecraft’s observations are painting a clear picture of how that magnetic field is changing. It’s heading to the poles at an average full-throttle pace of around 10 to 20 meters per second. This movement is important for understanding the sun’s eleven-year cycle. It includes two vast solar plasma wheels in each solar hemisphere.
It was hard for scientists on Earth to get a good look at the sun’s polar regions. This restricted perspective has rendered it almost completely infeasible to study the magnetic properties in those regions. Solar Orbiter data provides a missing piece to this puzzle. It provides essential information about the effects of the solar surface’s magnetic network on other layers of the sun, including casting shadows in the chromosphere above.
“To understand the sun’s magnetic cycle, we still lack knowledge of what happens at the sun’s poles. Solar Orbiter can now provide this missing piece of the puzzle,” – Sami Solanki, MPS director.
The supergranules at the poles are invaluable tracers. For the first time, they find the polar component of the sun’s global circulation. One supergranule consists of heated plasma and is two to three times the diameter of Earth. These enormous structures are found all over the solar surface, and their study has greatly improved our understanding of magnetic dynamics.
“The supergranules at the poles act as a kind of tracer. They make the polar component of the sun’s global, eleven-year circulation visible for the first time,” – Lakshmi Pradeep Chitta.
The research that led to these discoveries is now published in The Astrophysical Journal Letters. This study builds on our understanding of solar processes, which in turn helps us understand how they affect space weather and conditions here on Earth.