A mosaic image packed with 83 million pixels is providing an unprecedented view of the Sun and its tumultuous outer atmosphere.
It took Solar Orbiter around four hours to capture all 25 images that comprise the mosaic, which shows the Sun on March 7, 2022. At the time, the probe was 75 million kilometres away from the Sun, placing it roughly halfway between Earth and the star, according to an ESA press release. Launched in February 2020, Solar Orbiter is performing a series of eccentric solar orbits as it gets increasingly closer to our host star.
The 25 frames, captured by the probe’s Extreme Ultraviolet Imager (EUI), offer an unprecedented view of the Sun. EUI captured the image at a wavelength of 17 nanometres, the extreme ultraviolet region of the electromagnetic spectrum. ESA says it’s the highest resolution image ever taken of the Sun’s full disc and corona, or upper atmosphere.
High resolution, indeed. The stunning mosaic image consists of a 9,148 by 9,112 pixel grid, which ESA says is 10 times better than a 4K television. That amounts to a jaw-dropping 83 million pixels. ESA has provided an interactive graphic that allows you to move across the scene, and you can zoom in and out to take in some of the finer details. A high-res image, which I’m already using as my desktop wallpaper, can be found here.
At both the top right and bottom left, eerie dark filaments can be seen. These filaments can generate powerful eruptions, in which massive amounts of coronal gas get tossed into space. These blasts, if directed toward Earth, sometimes create solar storms in the vicinity of our atmosphere.
Another Solar Orbiter instrument, Spectral Imaging of the Coronal Environment (SPICE), is also providing meaningful data. SPICE peers deeper into the Sun, at a lower layer known as the chromosphere, which it does by scanning different wavelengths of extreme ultraviolet light produced by different atoms.
In a newly released SPICE gif, purple regions correspond to hydrogen gas at temperatures reaching 10,000 degrees Celsius, green to oxygen at 320,000 degrees C, and yellow to neon at 630,000 degrees C.
A big benefit of SPICE is that it’s allowing scientists to connect explosions on the surface to these deeper layers and to investigate an odd observation in which the Sun’s surface, at around 5,000 degrees C is actually cooler than the surrounding corona, which can reach 1 million degrees C.
Excitingly, Solar Orbiter is now days away from making its first close pass of the Sun, which will happen on March 26, 2022. All 10 of the probe’s instruments will be active at the time, as ESA scientists try to squeeze as much data from the flyby as possible. Solar Orbiter is now in an orbit that takes it closer to the Sun than Mercury. The probe will get progressively nearer over the next several years, while also gradually raising its orientation, which will allow for our first glimpse of the Sun’s polar regions.