The European Space Agency’s (ESA’s) Solar Orbiter is out of alignment with the rest of the Solar System. And that’s a good thing. By orbiting the Sun outside of the Solar System’s orbital plane, the spacecraft has captured the first clear images of the Sun’s south pole. According to the ESA, these observations (and other observations to come) will provide important insights into the Sun and its activity, with implications for the whole solar system.
“Today we reveal humankind’s first-ever views of the Sun’s pole,” said Carole Mundell, the director of science for the ESA, in a press release. “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.”
Read More: Solar Orbiter Sets Off for Mission to Study the Sun
The Sun's South Pole Perspective
Up until now, our observations of the Sun have occurred around the solar equator. That’s because all of the planets and operational spacecraft in our Solar System circle the Sun on the same orbital plane, and thus catch a similar angle of our closest star. But thanks to a flyby around Venus in February, the Solar Orbiter has now begun to orbit the Sun outside of this “ecliptic plane,” allowing the spacecraft to see the Sun from a new, high-latitude perspective.
On March 16 and 17, the Solar Orbiter took images at a 15-degree tilt from the Sun’s equator. On March 23, it took images at a steeper 17-degree angle. That allowed the spacecraft to clearly catch the Sun’s south pole for the very first time.
“We didn’t know what exactly to expect from these first observations,” said Sami Solanki, the director of the Max Planck Institute for Solar System Research and the team lead for the Solar Orbiter’s Polarimetric and Helioseismic Imager (PHI), according to the press release. “The Sun’s poles are literally terra incognita.”
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Messy Magnetism and a Solar Speed Map
According to the ESA, the Sun’s south pole was studied with three scientific instruments in March, including the Solar Orbiter’s PHI. This tool not only takes images of the visible solar surface; it also maps the invisible magnetic fields across that surface.
Harnessing the PHI, astronomers hope to learn more about the Sun’s magnetic field and solar cycle, an 11-year rhythm in which the Sun’s magnetic field rotates or reverses.
In fact, the Solar Orbiter’s high-latitude observations have already shown that the magnetic field at the Sun’s south pole is currently showing north and south polarity at the same time — a messy combination that occurs as the magnetic field flips, at the time of the Sun’s solar maximum. As the Sun thus approaches its next solar minimum, which will occur in 5 to 6 years, a single polarity will build up, overtaking the mixture of the two.
“How exactly this build-up occurs is still not fully understood,” Solanki said in the release. “So, [the] Solar Orbiter has reached high latitudes at just the right time to follow the whole process from its unique and advantageous perspective.”
Other initial observations include the first map of the speeds of the solar material moving within the Sun, a resource that could reveal more about the powerful streams of particles that the Sun shoots out into space. Making their way through the Solar System, these “solar winds” can cause auroras on Earth and can even prompt solar storms that mess with our satellites and power grids.
According to the ESA, these observations only scrape the surface of what we can gain from the Solar Orbiter’s tilted point of view.
“In the coming years, the spacecraft will climb further out of the ecliptic plane for ever better views of the Sun’s polar regions,” said Daniel Müller, the Project Scientist for the Solar Orbiter, according to the press release. “These data will transform our understanding of the Sun’s magnetic field, the solar wind, and solar activity.”
Read More: The Strongest Solar Storm in History Impacted Earth 14,300 Years Ago
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Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
