First ever look at the Sun’s south pole

All previous images of the Sun were taken from directly above the Sun’s equator. This is because Earth, the other planets, and spacecraft orbit the Sun within a flat disc called the ecliptic plane. Following a slingshot flyby of the planet Venus in February this year, Solar Orbiter has tilted out of this plane, revealing the Sun from a whole new angle.

This new viewing angle will help change our understanding of the Sun’s magnetic field, the solar cycle (an 11-year cycle of solar activity) and the workings of space weather. 

The image in yellow is from Solar Orbiter’s Extreme Ultraviolet Imager (EUI), an instrument which UCL researchers and engineers helped design, build and support. The image was taken on 23 March 2025, when Solar Orbiter was viewing the Sun from an angle of 17° below the solar equator, enough to directly see the Sun’s south pole. Over the coming years, the spacecraft will tilt its orbit even further up to 33°, so the best views – of both the north and south poles – are yet to come.

Dr Hamish Reid (Mullard Space Science Laboratory at UCL), the UK Co-Principal Investigator for the EUI, said: “This is humanity’s first look at either of the poles of the Sun. All our previous images of the Sun have been taken face-on with the Sun’s equator.  

“Spacecraft normally orbit the Sun on the flat disc called the ecliptic plane, just like most of the planets in our solar system.  This is the most energy efficient way to launch and maintain orbits.

“These first images of the solar poles are just the start. Over the next few years, there is scope for discovery science. We are not sure what we will find, and it is likely we will see things that we didn’t know about before.”  

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“We’ll see previously unobserved high-latitude flows that carry magnetic elements to the polar regions.  These flows sow the fundamental seeds for the next solar cycle.”

Solar Orbiter carries ten science instruments, all working together to investigate how our local star “works”. UCL scientists have played a leading role in two of them – the EUI, which images the Sun in ultraviolet light, and the Solar Wind Analyser.

Professor Chris Owen (Mullard Space Science Laboratory at UCL), Principal Investigator on the Solar Wind Analyser, said: “Solar Orbiter’s new vantage point will give us a fuller view of how solar wind expands to form a vast bubble around the Sun and its planets (known as the heliosphere). We will now see this happen in three dimensions, enhancing the single slice we get from observing only in the ecliptic plane.”

All eyes on the Sun’s south pole

The collage above shows the Sun’s south pole as recorded on 16–17 March 2025, when Solar Orbiter was viewing the Sun from an angle of 15° below the solar equator.

The images shown above were taken by three of Solar Orbiter’s instruments: the EUI, Polarimetric and Helioseismic Imager (PHI), and the Spectral Imaging of the Coronal Environment (SPICE) instrument.

The instruments each observe the Sun in a different way. PHI images the Sun in visible light (top left) and maps the Sun’s surface magnetic field (top centre). EUI images the Sun in ultraviolet light (top right), revealing the million-degree charged gas in the Sun’s outer atmosphere, the corona. The SPICE instrument (bottom row) captures light coming from charged gas at various temperatures above the Sun’s surface, thereby revealing different layers of the Sun's atmosphere.

Comparing and analysing the complementary observations made by these three imaging instruments shows how material moves in the Sun’s outer layers. This may reveal unexpected patterns, such as polar vortices (swirling gas) similar to those seen around the poles of Venus and Saturn.

These new observations are also key to understanding the Sun’s magnetic field and why it flips north and south poles roughly every 11 years, coinciding with a peak in solar activity. Current models and predictions of the 11-year solar cycle fall short of being able to predict exactly when and how powerfully the Sun will reach its most active state.

Messy magnetism at solar maximum

One of the first scientific findings from Solar Orbiter’s polar observations is the discovery that at the south pole, the Sun’s magnetic field is currently a mess. While a normal magnet, or a planet such as our Earth, has a clear north and south pole, the PHI instrument’s magnetic field measurements show that both north and south polarity magnetic fields are present at the Sun’s south pole.

This happens only for a short time during each solar cycle, at solar maximum, when the Sun’s magnetic field flips and is at its most active. After the field flip, a single polarity should slowly build up and take over the Sun’s poles. In five to six years from now, the Sun will reach its next solar minimum, during which its magnetic field is at its most orderly and the Sun displays its lowest levels of activity. 

Professor Sami Solanki, who leads the PHI instrument team from the Max Planck Institute for Solar System Research (MPS) in Germany, said: “How exactly this build-up occurs is still not fully understood, so Solar Orbiter has reached high latitudes at just the right time to follow the whole process from its unique and advantageous perspective.”

SPICE measures movement for the first time
Another interesting ‘first’ for Solar Orbiter comes from the SPICE instrument. SPICE measures the light (spectral lines) sent out by specific chemical elements – hydrogen, carbon, oxygen, neon and magnesium – at known temperatures. For the last five years, SPICE has used this to reveal what happens in different regions and different layers above the Sun’s surface.  The chemical signatures have been compared to those measured in the solar wind outflows passing the spacecraft itself by the Heavy Ion Sensor in the UCL-led SWA instrument suite to try to link these outflows to their source regions.

Now for the first time, the SPICE team has also managed to use precise tracking of spectral lines to measure how fast clumps of solar material are moving towards and away from the spacecraft. This is known as a ‘Doppler measurement’, named after the same effect that makes passing ambulance sirens change pitch as they drive by.  

Crucially, Doppler measurements can reveal how particles are flung out from the Sun in the form of solar wind. Uncovering how the Sun produces solar wind is one of Solar Orbiter’s key scientific goals, and measurement of the charged particles forming the solar wind passing the spacecraft is the key contribution of the UCL-led Solar Wind Analyser (SWA) suite. 

Professor Owen, Principal Investigator of the SWA suite, said: “The spacecraft moves very quickly around its closest approach to the Sun, which is inside the orbit of Mercury, so we actually move from maximum south to maximum north latitudes in only a few weeks around this time.

“We thus get an unprecedented south-north cut through the Sun’s main activity belt and the prospect of connecting the observed outflows from the solar surface at a variety of latitudes with those encountered at the spacecraft.  These connections are key to many of the prime mission goals.”

The best is yet to come
These are just the first observations made by Solar Orbiter from its newly inclined orbit, and much of this first set of data still awaits further analysis. The complete dataset of Solar Orbiter's first full ‘pole-to-pole' flight past the Sun is expected to arrive on Earth by October 2025. All ten of Solar Orbiter’s scientific instruments will collect unprecedented data in the years to come.

Dr Daniel Müller, ESA’s Solar Orbiter project scientist, said: “This is just the first step of Solar Orbiter’s ‘stairway to heaven’: in the coming years, the spacecraft will climb further out of the ecliptic plane for ever better views of the Sun’s polar regions. These data will transform our understanding of the Sun’s magnetic field, the solar wind, and solar activity.”

The spacecraft, which launched in February 2020, began the ‘high latitude’ part of its journey five years later, in February 2025.

Nearly all Sun-observing spacecraft have tilted from the ecliptic plane by no more than 7°.The exception to this is the ESA/NASA Ulysses mission (1990–2009), which flew over the Sun's poles but did not carry any imaging instruments and remained at much larger distances from the Sun itself.

Solar Orbiter’s observations will complement Ulysses’ by observing the poles for the first time with telescopes, in addition to a full suite of in-situ sensors, while flying much closer to the Sun where the solar wind can be sampled in a more pristine state. Additionally, Solar Orbiter will monitor changes at the poles throughout the solar cycle.

Solar Orbiter will continue to orbit around the Sun at this tilt angle until 24 December 2026, when its next flight past Venus will tilt its orbit to 24°. From 10 June 2029, the spacecraft will orbit the Sun at an angle of 33°.

Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.

Links

• ESA's story
• ESA Solar Orbiter
• Dr Hamish Reid’s academic profile
• Professor Lucie Green’s academic profile
• Professor Chris Owen’s academic profile
• UCL Mullard Space Science Laboratory
• UCL Mathematical & Physical Sciences

Images

• Top: A screenshot from the EUI video, described below.
• EUI video: This video starts with the Sun as viewed from Earth. The grey images were taken by the SWAP extreme ultraviolet telescope on ESA’s Proba-2 spacecraft. The dashed red-green lines show the solar latitudes and longitudes (Stonyhurst grid), while the solid yellow lines show the centre of Earth’s view. We then rotate to Solar Orbiter’s tilted view, shown in yellow, and zoom in to the Sun’s south pole. Solar Orbiter used its Extreme Ultraviolet Imager (EUI) instrument to take these images. What you see is million-degree charged gas moving in the Sun’s outer atmosphere, the corona. Every now and then, a bright jet or plume lights up this gas.

Credit: ESA & NASA/Solar Orbiter/EUI Team, D. Berghmans (ROB) & ESA/Royal Observatory of Belgium. License: CC BY-SA 3.0 IGO and ESA Standard Licence

• Middle: This collage shows Solar Orbiter's view of the Sun's south pole on 16–17 March 2025, from a viewing angle of around 15° below the solar equator. This was the mission’s first high-angle observation campaign, a few days before reaching its current maximum viewing angle of 17°.

These data were recorded by three of Solar Orbiter’s scientific instruments: the Polarimetric and Helioseismic Imager (PHI), the Extreme Ultraviolet Imager (EUI), and the Spectral Imaging of the Coronal Environment (SPICE) instrument. 

Credit: ESA & NASA/Solar Orbiter/PHI, EUI and SPICE Teams. License: CC BY-SA 3.0 IGO and ESA Standard Licence

• Bottom: This image shows a magnetic field map from Solar Orbiter's Polarimetric and Helioseismic Imager (PHI) instrument, centred on the Sun's south pole. Blue indicates positive magnetic field, pointing towards the spacecraft, and red indicates negative magnetic field.

Credit: ESA & NASA/Solar Orbiter/PHI Team, J. Hirzberger (MPS). License: CC BY-SA 3.0 IGO and ESA Standard Licence

Media contact

Mark Greaves

m.greaves [at] ucl.ac.uk

+44 (0)20 3108 9485