ESA/NASA spacecraft solves mystery of solar switchback - a magnetic phenomenon in solar wind


Devdiscourse News Desk | Paris | Updated: 12-09-2022 17:06 IST | Created: 12-09-2022 17:06 IST
ESA/NASA spacecraft solves mystery of solar switchback - a magnetic phenomenon in solar wind
Image Credit: ESA

The ESA/NASA Solar Orbiter spacecraft has solved the mystery of a magnetic phenomenon called solar switchbacks - sudden and large deflections of the solar wind's magnetic field.

On 25 March 2022, the NASA/ESA spacecraft was just a day away from its close approach to the Sun and the onboard Metis instrument was capturing data. Metis blocks out the bright glare of light from the Sun's surface and takes pictures of the corona - the Sun's outer atmosphere. The particles in the corona are electrically charged and follow the Sun's magnetic field lines out into space.

At around 20:39 UT, the instrument recorded an image of the solar corona that showed a distorted S-shaped kink in the coronal plasma - electrically charged particles.

Suspecting it to be a solar switchback, Daniele Telloni, National Institute for Astrophysics - Astrophysical Observatory of Torino, Italy, compared this Metis image with a concurrent image taken by Solar Orbiter's Extreme Ultraviolet Imager (EUI) instrument and saw that the candidate switchback was taking place above an active region catalogued as AR 12972.

Not only this, 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.

According to ESA, close to the Sun, and especially above active regions, there are open and closed magnetic field lines. Daniele and Prof. Gary Zank, the University of Alabama in Huntsville, USA, proved that switchbacks occur when there is an interaction between a region of open field lines and a region of closed field lines. As the field lines crowd together, they can reconnect into more stable configurations. Rather like cracking a whip, this releases energy and sets an S-shaped disturbance travelling off into space, which a passing spacecraft would record as a switchback.

"I would say that this first image of a magnetic switchback in the solar corona has revealed the mystery of their origin" says Daniele.

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