These are exceptional images. The Euro-American probe Solar Orbiter delivered this Thursday the closest images ever taken of the Sun, revealing miniature eruptions called "campfires", which could explain why it is so hot in the solar corona, one of the phenomena the most mysterious of our star.
Here they are, the images you all have been waiting for!
Enjoy #TheSunUpClosehttps: //t.co/VzhyZnKmRvpic.twitter.com/41LOAMJ3oc
Photos taken halfway between Earth and the Sun
The probe, which launched on February 10 with ten instruments on board, including six observation telescopes, took these shots 77 million kilometers from our star, or about halfway between Earth and Sun. They allowed scientists to observe "campfires" everywhere on the surface of the star. "The Sun may seem calm at first glance, but when we look in detail, we can see these miniature eruptions wherever we look," says David Berghmans of the Royal Observatory of Belgium.
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Yes, # SolarOrbiter's first images reveal 'campfires' on the Sun! https://t.co/VzhyZnKmRv
These images are from the Extreme Ultraviolet Imager (EUI) instrument. Credits: Solar Orbiter / EUI Team / ESA & NASA; CSL, IAS, MPS, PMOD / WRC, ROB, UCL / MSSL pic.twitter.com/PIltmsBp2P
The "Grail" of solar physics
And according to experts, these eruptions could explain why it is so hot in the solar corona, the outermost layer of the solar atmosphere which extends over several million kilometers. "The theorists, colleagues and we, in our team, have envisioned that there are small eruptions which precisely deposit their energy (…) in the crown", summarizes at the microphone of Europe 1 Tahar Amari, astrophysicist at Polytechnic.
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"This energy will heat the crown and bring it to a temperature of one or even two million degrees, while we could expect a drop in temperatures as we move away from the Sun." An increase all the more impressive since the surface of the star reaches "only" 5,500 degrees. At a press conference, ESA also stressed that understanding these mechanisms would be the "Grail" of solar physics.
And these images are only the beginning of this mission carried out jointly by the European Space Agency (ESA) and NASA. Solar Orbiter must indeed continue its journey to capture images of the poles of the Sun, but also measure the magnetic field of our star, which is still very mysterious.