With contemporary records from its closest move of the Solar so far, the ESA/Solar Orbiter has made the first-ever remote sensing observation consistent with a magnetic phenomenon called a solar switchback – sudden and large deflections of the solar wind’s magnetic field. The new observation provides a full view of the structure, confirming it has an S-shaped character, as predicted. Moreover, the global perspective provided by the Solar Orbiter data indicates that these rapidly changing magnetic fields can have their origin near the surface of the Sun.
An in depth-up view of the Sun Orbiter Metis records changed into a film presentations the evolution of the switchback. The collection represents round 33 mins of information taken on March 25, 2022. The brilliant construction bureaucracy whilst propagating outwards from the Solar. Because it reaches its complete construction it bends again on itself and acquires the distorted S-shape feature of a magnetic switchback. The construction expands at a pace of 80 km/s however the entire construction does no longer transfer at this pace. As a substitute, it stretches and distorts. That is the 1st time a magnetic switchback has ever been seen remotely. All different detections have taken position when spacecraft have flown thru those disturbed magnetic areas. Credit score: ESA & NASA/Sun Orbiter/Metis Groups; D. Telloni et al. (2022)
Even though a variety of spacecraft have flown thru those puzzling areas sooner than, in situ records best permit for a size at a unmarried level and time. As a outcome, the construction and form of the switchback must be inferred from
These magnetic structures were also probed at much larger distances from the Sun by the Ulysses spacecraft in the late 1990s. Instead of a third of the Earth’s orbital radius from the Sun, where the Helios missions made their closest pass, Ulysses operated mostly beyond the Earth’s orbit.
Their number rose dramatically with the arrival of NASA’s Parker Solar Probe in 2018. This clearly indicated that the sudden magnetic field reversals are more numerous close to the Sun, and led to the suggestion that they were caused by S-shaped kinks in the magnetic field. This puzzling behavior earned the phenomenon the name of switchbacks. A number of ideas were proposed as to how these might form.
On March 25, 2022, Solar Orbiter was just a day away from a close pass of the Sun – bringing it within the orbit of planet Mercury – and its Metis instrument was taking data. Metis blocks out the bright glare of light from the Sun’s surface and takes pictures of the Sun’s outer atmosphere, known as the corona. The particles in the corona are electrically charged and follow the Sun’s magnetic field lines out into space. The electrically charged particles themselves are called a plasma.
At around 20:39 UT, Metis recorded an image of the solar corona that showed a distorted S-shaped kink in the coronal plasma. To Daniele Telloni, National Institute for Astrophysics – Astrophysical Observatory of Torino, Italy, it looked suspiciously like a solar switchback.
Comparing the Metis image, which had been taken in visible light, with a concurrent image taken by Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument, he saw that the candidate switchback was taking place above an active region cataloged as AR 12972. Active regions are associated with sunspots and magnetic activity. Further analysis of the Metis data showed that the speed of the plasma above this region was very slow, as would be expected from an active region that has yet to release its stored energy.
Daniele instantly thought this resembled a generating mechanism for the switchbacks proposed by Prof. Gary Zank, from the University of Alabama in Huntsville, USA. The theory looked at the way different magnetic regions near the surface of the Sun interact with each other.
ESA’s Sun Orbiter has solved the thriller of a magnetic phenomenon within the sun wind. It has taken the first-ever symbol of a ‘switchback’ within the sun corona, confirming its predicted ‘S’ form. A switchback is outlined by way of speedy flips within the magnetic box course. The seen switchback is connected to an energetic area related to sunspots and magnetic task the place there’s an interplay between open and closed magnetic box traces. The interplay releases power and sends the S-shaped disturbance into house. The brand new records counsel that switchbacks may originate close to the sun floor, and is also necessary in figuring out the acceleration and heating of the sun wind. Credit score: ESA
On the subject of the Solar, and particularly above energetic areas, there are open and closed magnetic box traces. The closed traces are loops of magnetism that arch up into the sun surroundings sooner than curving spherical and disappearing again into the Solar. Little or no plasma can get away into house above those box traces and so the rate of the sun wind has a tendency to be sluggish right here. Open box traces are the opposite, they emanate from the Solar and connect to the interplanetary magnetic box of the Sun Gadget. They’re magnetic highways alongside which the plasma can drift freely, and provides upward push to the short sun wind.
Daniele and Gary proved that switchbacks happen when there’s an interplay between a area of open box traces and a area of closed box traces. As the sphere traces crowd in combination, they are able to reconnect into extra solid configurations. Relatively like cracking a whip, this releases power and units an S-shaped disturbance touring off into house, which a passing spacecraft would report as a switchback.
In line with Gary Zank, who proposed some of the theories for the foundation of switchbacks, “The primary symbol from Metis that Daniele confirmed urged to me nearly straight away the cartoons that we had drawn (see symbol above) in creating the mathematical type for a switchback. In fact, the 1st symbol used to be only a snapshot and we needed to mood our enthusiasm till we had used the superb Metis protection to extract temporal knowledge and do a extra detailed spectral research of the photographs themselves. The effects proved to be completely impressive!”
Along side a workforce of alternative researchers, they constructed a pc type of the conduct, and located that their effects bore a putting resemblance to the Metis symbol, particularly when they integrated calculations for the way the construction would elongate all over its propagation outwards in the course of the sun corona.
“I’d say that this primary symbol of a magnetic switchback within the sun corona has printed the thriller in their foundation,” says Daniele, whose effects are revealed in a paper in The Astrophysical Magazine Letters.
In figuring out switchbacks, sun physicists can be taking a step towards figuring out the main points of ways the sun wind is sped up and heated clear of the Solar. It’s because when spacecraft fly thru switchbacks, they continuously sign up a localized acceleration of the sun wind.
“The next move is to check out to statistically hyperlink switchbacks seen in situ with their supply areas at the Solar,” says Daniele. In different phrases, to have a spacecraft fly in the course of the magnetic reversal and be capable of see what’s took place at the sun floor. That is precisely the type of linkage science that Sun Orbiter used to be designed to do, but it surely does no longer essentially imply that Sun Orbiter must fly in the course of the switchback. It may well be any other spacecraft, akin to Parker Sun Probe. So long as the in-situ records and faraway sensing records is concurrent, Daniele can carry out the correlation.
“That is precisely the type of consequence we had been hoping for with Sun Orbiter,” says Daniel Müller, ESA Mission Scientist for Sun Orbiter. “With each orbit, we download extra records from our suite of ten tools. In line with effects like this one, we will be able to fine-tune the observations deliberate for Sun Orbiter’s subsequent sun stumble upon to grasp the way in which through which the Solar connects to the broader magnetic atmosphere of the Sun Gadget. This used to be Sun Orbiter’s first actual shut move to the Solar, so we predict many extra thrilling effects to return.”
Sun Orbiter’s subsequent shut move of the Solar – once more inside the orbit of Mercury at a distance of 0.29 occasions the Earth-Solar distance – will happen on 13 October. Previous this month, on 4 September, Sun Orbiter made a gravity lend a hand flyby at DOI: 10.3847/2041-8213/ac8104