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The new data give us more insight into how the Sun’s magnetic field polarity reversal occurs, which is crucial for improving current models of the solar activity cycle and enhancing long-term predictions of solar storms.
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Photograph of the bottom half of the Sun, with a highlighted square region around the Sun's south pole. Taken in ultraviolet light, the image shows the hot gas in the Sun's outer atmosphere, the corona, glowing yellow as it extends outwards in threads and loops from the Sun.
Credits
ESA & NASA/Solar Orbiter/EUI Team, D. Berghmans (ROB)

The Solar Orbiter mission, a joint initiative between the European Space Agency (ESA) and NASA, has captured the first detailed images of the Sun’s south pole — a region previously unexplored. These groundbreaking observations were possible thanks to the spacecraft’s inclined orbit and its advanced instrumentation, which allows scientists to study the different layers of the solar atmosphere and measure the magnetic field at the Sun’s surface.
The Sun has a highly dynamic magnetic field that follows a cycle of approximately 11 years. During this period, solar activity — such as sunspots, solar flares, and coronal mass ejections — increases and decreases. At the midpoint of the cycle, a fascinating phenomenon occurs: the reversal of the Sun’s magnetic field polarity. This means that the magnetic north pole becomes south, and vice versa.

 

This infographic by the European Space Agency, titled "Why Solar Orbiter is Angling Towards the Sun's Poles", illustrates the mission’s unique trajectory and scientific goals. At the centre of the image, the Sun is shown with dynamic magnetic field lines, emphasizing polar activity. To the left, the Solar Orbiter spacecraft is depicted with its orbital path marked for 2025 and 2028, showing how it gradually tilts to observe the Sun’s poles. The top right explains the solar dynamo mechanism, while the bottom right highlights the role of polar observations in understanding space weather and the Sun’s global magnetic field.
Credit: ESA & NASA/Solar Orbiter

 

This process is neither instantaneous nor uniform. It begins with a reorganization of the magnetic field at mid-latitudes and eventually affects the poles. That’s why observing the Sun’s poles is key to understanding how this reversal happens and how it influences the Sun’s behavior and space weather.
The images reveal a “messy” magnetic field at the south pole, with both positive and negative polarities present. This phenomenon is linked to the fact that the Sun is currently at the peak of its activity cycle, a phase during which the polarity of its magnetic field reverses.
“The new data provided by Solar Orbiter give us more insight into how the Sun’s magnetic field polarity reversal occurs, especially in regions for which we previously had no data. This is crucial for improving current models of the solar activity cycle and, consequently, for enhancing long-term predictions of solar storms,” explains Dr. Àngels Aran, researcher of the Institute of Cosmos Sciences of the University of Barcelona and the Institute of Space Studies of Catalonia (ICCUB-IEEC).
 

 

The ICCUB-IEEC has played a key role in this scientific milestone. A team led by Dr. José Maria Gómez-Cama, ICCUB-IEEC researcher and member of the Department of Electronic and Biomedical Engineering at the University of Barcelona (UB), was responsible for developing and implementing the Image Stabilization System (ISS) of the PHI (Polarimetric and Helioseismic Imager) instrument. This system compensates for spacecraft motion to ensure high-quality imaging, such as the recent captures of the Sun’s south pole.

 

This composite image from the ESA-led Solar Orbiter mission showcases the Sun observed across eight different wavelengths, each revealing distinct layers and temperatures of the solar atmosphere. The top row presents the Sun’s photosphere in visible light, a magnetic field map, and the corona in extreme ultraviolet. The bottom row spans ultraviolet observations from 10000 °C to over 1.2 million °C, highlighting emissions from hydrogen, carbon, oxygen, neon, and magnesium. These multi-wavelength views help scientists understand the Sun’s complex structure and dynamic behaviour across its outer layers.
Credit: SA & NASA/Solar Orbiter/PHI, EUI and SPICE Teams

Additionally, the Heliospheric Physics and Space Weather group at ICCUB and the Department of Quantum Physics and Astrophysics has provided scientific support to the team behind the Energetic Particle Detector (EPD) instrument, developing models to predict particle radiation levels during solar storms — a key factor for mission safety.
Launched in February 2020, Solar Orbiter aims to study the Sun up close and from unique perspectives, particularly its poles, to better understand its magnetic behavior and its influence on the interplanetary environment. In the coming years, the spacecraft’s orbital inclination will gradually increase thanks to gravity-assist maneuvers around Venus. This will allow for even more detailed imaging of the solar poles, opening a new chapter in our understanding of the solar cycle and space weather.