Latest news with #solarresearch
Gizmodo
2 days ago
- Science
- Gizmodo
Solar Orbiter Captures First Clear Views of Sun's South Pole—and It's a Hot Mess
For more than 60 years, various spacecraft and telescopes have journeyed through space to stare at the Sun, capturing haunting images of the giant ball of hot gas at the heart of our solar system. Our view of the star is limited, however, by Earth's orbital plane, which allows us to observe the Sun's equator head-on while its polar regions remain in a frustrating blind spot. Solar Orbiter is now the first to image the poles from outside the ecliptic plane, offering a rare look at its chaotic magnetic field. On Wednesday, the European Space Agency (ESA) released the first clear images of the Sun's south pole, revealing that both north and south magnetic polarities are currently present on the same side. The new images will help scientists better understand the Sun's 11-year magnetic cycle and what governs its solar outbursts that sometimes result in geomagnetic storms on Earth. Solar Orbiter used momentum from its flyby of Venus on February 18 to push itself out of the ecliptic plane that contains Earth's orbit around the Sun. Around a month later, the spacecraft was able to view the star from an angle of 17 degrees below the solar equator, just enough to get a good view of the Sun's south pole for the first time. 'We didn't know what exactly to expect from these first observations – the Sun's poles are literally terra incognita,' Sami Solanki, who leads Solar Orbiter's Polarimetric and Helioseismic Imager instrument team from the Max Planck Institute for Solar System Research in Germany, said in a statement. The science team used three instruments aboard Solar Orbiter to capture images of the Sun between March 16 and 17. Each instrument observes the Sun in a different way; the Polarimetric and Helioseismic Imager (PHI) captures the Sun in visible light, the Extreme Ultraviolet Imager (EUI) images it in ultraviolet, and the Spectral Imaging of the Coronal Environment (SPICE) instrument detects light emitted by charged gas above the Sun's surface. By combining the viewing powers of all three instruments, scientists observed the Sun's south pole in turmoil. Normally, each polar region has its own magnetic field characteristics. As the Sun reaches a period of solar maximum during its 11-year cycle, its magnetic polarity flips, with the north and south magnetic poles reversing. During Solar Orbiter's observations of the Sun, the polarity from the north and the south poles are both present in the south pole. This marks a crucial time in understanding the Sun's activity. After the magnetic field flips, a single polarity slowly builds up in the Sun's poles and takes over. When the Sun reaches its solar minimum in about five to six years, the north and south poles will each have their own magnetic polarity. '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,' Solanki said. The scientists behind the mission used SPICE to measure how clumps of solar material move across the Sun's surface. Using the Doppler effect, which describes changes in frequency of light or sound as it moves away or toward the source, the team created a velocity map showing how the material's speed varies between the Sun's poles and equatorial region. With the help of Solar Orbiter, scientists will gain a better understanding of why solar wind travels faster at the poles than it does at the Sun's equator. Solar Orbiter is just getting started. The recent observations are the first set of images captured from the spacecraft's newly inclined orbit, but the spacecraft is gearing up for another Venus flyby on December 24, 2026, which will further tilt its orbit to 23 degrees below the equator to get an even better view of the Sun's poles. '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,' Daniel Müller, ESA's Solar Orbiter project scientist, said in a statement. 'These data will transform our understanding of the Sun's magnetic field, the solar wind, and solar activity.'
The Guardian
2 days ago
- Science
- The Guardian
Sun's south pole revealed for first time, in images from Solar Orbiter spacecraft
The sun's uncharted south pole has been revealed for the first time in striking images beamed back from the Solar Orbiter spacecraft. The joint European Space Agency (ESA) and Nasa mission swooped below the planetary plane and, for the first time, captured the sun's mysterious polar regions. The groundbreaking observations also mapped a chaotic patchwork of magnetic activity at the sun's pole that scientists say is key to understanding how the sun's field flips roughly every 11 years. 'Today we reveal humankind's first-ever views of the sun's pole,' said Prof Carole Mundell, the ESA's director of science. 'The sun is our nearest star, giver of life and potential disruptor of modern space and ground power systems, so it is imperative that we understand how it works and learn to predict its behaviour. These new unique views from our Solar Orbiter mission are the beginning of a new era of solar science.' The $1.3bn mission, which launched in 2020, shows the sun's south pole as recorded mid-March, when the craft had dipped to an angle of 15° below the solar equator to perform the mission's first high-angle observations. While the Earth – like a bar magnet – has a clear north and south, the sun's magnetism flips roughly every 11 years. The sun is currently at a solar maximum, the period when it builds up to a polarity flip, in which the south pole will become magnetic north and when sun spots and solar flares are most active. Solar Orbiter's first magnetic field measurements reveal a fragmented mosaic of both north and south polarity at the base of the sun. This patchwork of north and south had been predicted in computer models, but had never been confirmed in observations. Scientists say that tracking the dramatic changes in the sun's polar magnetic fields will be crucial to improving forecasting of the solar cycle. 'We didn't know what exactly to expect from these first observations – the sun's poles are literally terra incognita,' said Prof Sami Solanki, who leads the instrument mapping the magnetic field and is based at the Max Planck Institute for Solar System Research (MPS) in Germany. The sun's magnetic cycle occurs because it does not rotate as a solid object, with its equator spinning faster (every 26 days) than its poles (33 days). This stretches and twists magnetic field lines around the sun until they become so unstable that north and south eventually flip. Prof Lucie Green, of UCL's Mullard Space Science Laboratory, who has worked on the mission since 2005, said: 'Everything in the atmosphere of the sun and whole character of the sun is generated by its magnetic field and how that changes over time. It goes from being a fairly quiet star to being really active and dynamic star with explosions in the atmosphere. Although the models predicted that the field should be mixed up, it's something else to actually see it.' In five or six years, the sun will reach its next solar minimum, during which its magnetic field is at its most orderly and the sun has the lowest levels of 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. The only previous mission to have flown above the sun's poles was Nasa's Ulysses probe, launched in 1990, but while it took measurements of the sun's magnetic field and solar wind, it did not have a camera. Solar Orbiter will continue to orbit around the Sun at a 17° tilt angle until 24 December 2026, when its next flight past Venus will tilt its orbit to 24° and in 2029, the spacecraft will rise to an angle of 33° above the planetary plane.
