Thanks to coordinated measures between the European Solar Orbiter mission and those of the NASA’s Parker probe, a scientific team was able to explain the origin of the extreme temperatures of the solar corona. The latter is hotter than the solar “surface”. The fault of turbulent jets?
This is the first time that a simultaneous double measurement has been carried out between the two. The logistics of such a measure are such that it could only occur in a very short time window.
However, Italian researcher Daniele Telloni (Turin observatory) was not impressed by the task. Responsible for the METIS instrument on the European Solar Orbiter probe which was recently hit by a solar flare, he patiently waited for such an option to become possible. METIS is a coronagraph, it is equipped to hide the solar surface and precisely observe the characteristics of the corona, which can be defined as the atmosphere of our star. Enough to obtain a global vision of the phenomena that take place there!
Alignment of ships
But, what if these measurements could be correlated by another vehicle, passing at the same time directly in the solar corona? This was the case on June 1, 2022, with a passage by NASA’s Parker probe. Immediately, the teams worked together to obtain this Holy Grail: remote measurements and in situ data, at the same time.
Parker solar orbiter (and vice versa)
The problem for measurements of the solar corona is that in fact the events which occur there are very short, and very dynamic: measurements a few hours or days apart cannot provide as much precision as a simultaneous observation! Especially since it has been possible to measure temperatures there, the mystery remains.
The solar surface is heated to around 6,000°C, while temperatures reach and even exceed 1 million degrees Celsius in the corona! A factor of 150 that is difficult to explain theoretically… And yet! With this double campaign from Solar Orbiter and Parker Solar Probe, the explanation is within reach. Researchers have in fact observed and measured turbulent jets within the different layers of the solar corona, and it is these turbulences (plasma, but also magnetic), which, like whiplashes, generate extreme temperatures.
A first step to explaining temperatures
“ This is a scientific first, this work represents a big step forward in solving the problem of coronal heat », explains researcher Daniel Müller. His colleague Daniele Telloni, who initiated the double measurement, is already working on confirmation, although it will take time to prepare everything, as well as to study the future data. Combining in situ data with distant measurements requires orbital gymnastics, but also resources to analyze the results which could answer one of the great enigmas concerning our Sun!
Source : esa
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