Why is the Sun's outer atmosphere much hotter than its surface? Scientists are close to solving a 65-year-old mystery

September 18, 2023  22:22

The temperature of the Sun's atmosphere is incredibly high: it reaches a million degrees, which is 150 times higher than the surface temperature of the star. For more than 6 decades, scientists could not understand how this could be, because it is generally accepted that the temperature should decrease with distance from the heat source. Now scientists seem to be closer to solving this mystery: a unique collaboration between the Solar Orbiter and Parker Solar Probe spacecraft can help them.

Scientists have turned their attention to the process of turbulence, which is believed to play an important role in heating the solar corona. They compared it to stirring coffee in a cup: energy is transferred from large scales to smaller ones, including interaction with individual particles, mainly protons, heating them. Magnetic fields present in the corona further enhance this process.

To study this phenomenon in more detail, scientists used the Solar Orbiter and Parker Solar Probe spacecraft. Solar Orbiter carried out remote sensing and also took measurements closer to the Sun, which allowed us to gain a more complete understanding of the processes under study.

However, the key moment was the Solar Orbiter maneuver, which included a 45-degree turn and deviation from the original course. This is a risky step, but thanks to it, the device was able to focus on a specific area and, together with Parker Solar Probe, collect unique data.

After comparing the new measurements with the theoretical predictions of physicists, scientists came to the conclusion that the role of turbulence in heating the solar corona is confirmed. This important discovery will allow us to study the mechanisms of this process in more detail and expand knowledge about the Sun.

Daniel Müller, one of the scientists working on the project, noted that this work opens a new chapter in research and calls it a significant step forward in solving the problem of heating the solar corona. Now scientists have the opportunity to better understand the processes occurring in this amazing space object.

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