⇧ [VIDÉO] You may also like this affiliate content (after ads)
The sun in all its glory, in an image so detailed it will take your breath away. This is the latest feat achieved by the Solar Orbiter probe, the European Space Agency’s (ESA) space surveillance satellite dedicated to studying our star. Created by the Extreme Ultraviolet Imager (EUI) telescope, the unprecedented composite image of the Sun is the result of photographs taken on March 7 at about 75 million kilometers from Earth. This is the highest resolution image of the full disk of the Sun, its outer atmosphere and corona to date. These data, in particular, will allow a deeper understanding of solar flares. The temperature difference between its surface and its crown, which is still a mystery to scientists, can also be studied more closely.
To capture the image, the EUI telescope had to take 25 separate shots. The device, in particular, captures images at such a high resolution that, when too close to its target, it is necessary to create a mosaic of negatives in order to then assemble them to form a single complete image. It then took the telescope more than four hours to cover the entire Sun, counting about 10 minutes for each part, plus the time it took for the spacecraft to get the lens from one corner to another.
Finally, 25 shots together produce an image of over 83 million pixels in a 9148 x 9112 pixel frame. For comparison, 4K resolution is 10 times lower. In addition, by passing exactly between the Earth and the Sun, Solar Orbiter took pictures that can be compared with ground-based instruments already taken. These comparative data are very valuable for understanding how the Sun works.
Better understand solar flares and atmospheric temperatures
Located at a wavelength of 17 nanometers, in the extreme ultraviolet electromagnetic spectrum, the image very clearly shows the corona (upper atmosphere) of the Sun. At 2 and 8 o’clock, the image also shows dark filaments on its surface. Such gigantic bubbles are especially likely to burst, causing solar flares that will eject gigantic amounts of matter into the corona and into space.
In addition, Solar Orbiter also photographed our star in the Lyman-beta wavelength range of ultraviolet light emitted by hydrogen (in its gaseous state at a temperature of 10,000°C). This is the first image of its kind in 50 years taken by the probe’s Spectral Coronal Environment Imager (SPICE). The device is actually designed to observe the layers of the Sun’s atmosphere, from the corona to the chromosphere (the lower solar atmosphere, located between the photosphere and the corona and visible only during total eclipses). To do this, the device analyzes different wavelengths in the extreme ultraviolet emitted by different atoms such as hydrogen, oxygen, carbon and neon.
Once collected, this data will allow ESA scientists to track solar flares occurring in the photosphere. These particularly strong phenomena eject millions of tons of ionized matter into the corona several hundred thousand kilometers above sea level.
In addition, temperature changes in the upper atmosphere will be more widely observed. This is one of the most mysterious phenomena in astrophysics, because logically, the temperature should decrease as you move away from a hot object. However, at the Sun, the temperature of the corona reaches a million degrees Celsius, and lower on the surface the temperature is “only” about 5000 ° C. According to the ESA statement, investigating this mystery is one of the main goals of Solar Orbiter.
On the 26th of this month, Solar Orbiter marked a milestone by reaching its perihelion (the point in its orbit where its distance from the Sun is closest) for the first time. The spacecraft is now inside the orbit of Mercury, the planet closest to the Sun.
Highest possible resolution images of our star are expected, as well as data on the solar wind. In the next few years, ESA also plans to image rarely observed regions of the Sun, such as its poles.