Since its launch in February 2020, the Solar Orbiter spacecraft has been using its vast array of scientific instruments to unravel some of the mysteries surrounding our sun. Using a specialised ultraviolet camera, the Solar Orbiter recently took some of the highest-quality images of the outer atmosphere, the so-called corona of the Sun, in the history of astronomy.
The images, which have incredible resolution, were taken because the Extreme Ultraviolet Imager was tuned specifically for wavelengths emitted by the Sun's corona, which can reach temperatures of up to a million degrees Celsius.
Solar Orbiter was 75 million kilometres away from the Sun when it took this image on March 7. During four hours, the probe took 25 separate images, from which the final image was synthesized. The resolution of the final image is more than 83 million pixels (9 148 x 9 112 pixels), about 10 times the resolution of the 4K standard.
At the same time, the tool Spectral Imaging of the Coronal Environment (SPICE) was also used, which is capable of extracting light at wavelengths corresponding to the spectral lines of the atoms of the various chemical elements from the light beam. This allows the instrument to look deep inside the Sun, below the corona, into a layer called the chromosphere, and to measure its temperature.
The last image shown here shows the Sun glowing at different wavelengths. Violet corresponds to the emission of hydrogen at 10 thousand degrees, blue is the glow of carbon at 32 thousand degrees, green is oxygen at 320 thousand degrees and yellow is neon at 630 thousand degrees. Such data will help scientists understand the temperature distribution in the Sun's upper layers and find an answer to the question of why the temperature in the corona is much higher than the surface temperature, which is only 5 thousand degrees.