Emily Chan
Scientists have wondered for decades why the sun’s outer atmosphere, known as the corona, heats up the farther away it gets from the surface of the sun.
Now, thanks to data collected by NASA’s Parker Solar Probe, an explanation has finally been narrowed down.
The probe was launched in 2018 with the mission of swooping within four million miles of the sun’s surface to make observations of the corona.
The corona is a hundred times hotter than the sun’s surface, or the photosphere, despite being farther away from the source of heat at the sun’s core.
Even though the photosphere is cooler than the corona, it is responsible for the light that emanates from the sun.
To study the corona, the Parker Solar probe must brave temperatures of around 2,500 degrees Fahrenheit, facing heat and radiation that no other spacecraft has ever experienced.
During the probe’s first encounters with the sun, it detected S-shaped bends in the sun’s magnetic field, which scientists named “switchbacks” due to how they caused abrupt reversals in the direction of the magnetic field.
It was suspected that the switchbacks release magnetic energy as they travel through space, eventually straightening out.
“That energy has to go somewhere, and it could be contributing to heating the corona and accelerating the solar wind,” said Mojtaba Akhavan-Tafti, a co-author of the study and an assistant research scientist for climate and space sciences and engineering at the University of Michigan.
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