The Sun’s inner corona appears faint yellow in this image taken on 25 March 2025 by the ASPIICS coronagraph aboard Proba-3, ESA’s formation-flying mission capable of creating artificial total solar eclipses in orbit.
The ASPIICS instrument captures the solar corona in two different ‘spectral lines’, each line corresponding to a different element contained in the coronal gases.
This image, captured in the spectral line emitted by helium atoms, shows the solar corona similarly to how a human eye would see it during an eclipse through a yellow filter.
A grid shows the true position of the Sun behind the mission’s occulter, slightly off-centre. This image was acquired while the ASPIICS instrument was off-pointed, bringing the bright disc of the Sun as close as possible to the occulter’s edge. Even in this position, ASPIICS was able to make detailed observations, as demonstrated by a cloud of cold plasma visible in the top right.
Andrei Zhukov, ASPIICS Principal Investigator, explains: “The corona is extremely hot, about two hundred times hotter than the solar surface itself. Sometimes, clouds of relatively cold plasma are observed near the Sun – although these are still around 10 000 degrees, they are much colder than the surrounding million-degree hot plasma – creating what we call ‘a prominence’. We are very happy to have been able to capture one such structure in one of the first ASPIICS images.”
See more images from Proba-3’s first artificial solar eclipse here.
[Image description: This is an image of the Sun taken during an artificial solar eclipse. Against a black background, the Sun’s bright body is covered by a black disc. On this disc, a plot-like grid shows the real position and orientation of the Sun behind it, tilted with the north slightly to the right. Faint yellow light peeks from behind the black disc’s edge, slowly fading towards the outer edges of the image. Close to the disc’s edge, in the top right, a small cloud of bright yellow is visible.]