First artificial solar eclipse from space captured by ESA Proba-3 mission
These images will help scientists unravel the mysteries of the Sun's super-hot corona.
A satellite duo orbiting our planet has just captured the very first images of an artificial solar eclipse from space, providing us with a spectacular view of the Sun's corona — a view only rarely available to us here on Earth.
Total solar eclipses are amazing to behold. They spark awe and wonder in those fortunate enough to witness the event. Also, the brief moments of totality give us a chance to see and study parts of the Sun that are nearly impossible to observe at any other time.
The April 8 total solar eclipse, imaged from Dallas, Texas, during 'totality', when the Moon completely blocked the Sun. While a few red-tinged prominances are visible along the edge of the Moon, the primary feature we see is the solar corona, which is shaped and sculpted by the Sun's powerful magnetic fields. (NASA/Keegan Barber)
The solar corona is the Sun's atmosphere. It is the source of the solar wind, which constantly flows past our planet and causes auroras to shine near the north and south poles. It also holds one of the biggest mysteries of our solar system, as it reaches temperatures of about 1 million degrees Celsius, while the surface of the Sun (the photosphere) is only around 5,500°C.
There have been clues over the years, but overall, scientists are still trying to find out exactly why the corona is so much hotter than the photosphere.
The main reason for this is that studying the corona is challenging. We can see it during a total solar eclipse, but those are few and far in-between. And even when one does occur, the time they have to observe it — right at totality — only lasts for a few minutes each time. Jets have been able to extend this time a bit, as they fly straight down the path of totality, but the shadow of the Moon moves too quickly to get a sustained look.
Special cameras known as coronagraphs give us longer observations of the corona. Two flying in space right now, one on the NASA/ESA Solar and Heliospheric Observatory (SOHO) and the other on the GOES-19 weather satellite, have a small disk at the end of an arm positioned in front of the camera lens to cover the Sun.
Two composite views of the Sun from SOHO and the Solar Dynamics Observatory show the outer parts of the solar corona. As the innermost part of each image reveals, there is a lot of space between the inner edge of SOHO's coronagraph view and the surface of the Sun, which means we do not get a consistent look at the inner corona. (NASA SDO/NASA-ESA SOHO/Scott Sutherland)
With that disk in place, the sensitive camera can then pick up the much fainter activity going on around the Sun. However, when scientists fly one of these instruments, they have to account for the entire range of distance the satellite will be from the Sun, thus the disk has to give a lot of leeway, to prevent the Sun from peaking around the edge of the coronagraph and burning out the optics. Thus, these coronagraphs can never give us as good a view of the corona as we see during a total solar eclipse, where we can even view the very lowest layers of the Sun's atmosphere.
The European Space Agency's Proba-3 mission solves that problem, though. The two satellites that are part of the mission — the Coronagraph and the Occulter — fly in precise formation, orbiting around the Earth. Each time they come around on the Sun-ward side of the planet, they line up perfectly, at just the right distance, that the Occulter perfectly covers up the Sun's disk, just like the Moon does during a total solar eclipse.
Proba-3's Coronagraph and Occulter fly in tandom as they loop around the sunward side of Earth, with the Occulter at the precise distance to block the Sun's disk for the camera. (ESA)
Now, Proba-3 has sent back its very first artificial solar eclipse images, and the results are pretty amazing.
"Seeing the first data from ASPIICS is incredibly exciting," Joe Zender, Proba-3 project scientist, said in an ESA press release. "Together with the measurements made by another instrument on board, DARA, ASPIICS will contribute to unravelling long-lasting questions about our home star."
The Sun’s inner corona is revealed in this image taken by Proba-3's ASPIICS coronagraph, on May 23, 2025. The image shows the corona similar to how the human eye would see it during an eclipse, but through a green filter. The details of the image were enhanced by a specialized image processing algorithm. (ESA)
"Each full image — covering the area from the occulted Sun all the way to the edge of the field of view — is actually constructed from three images," said Andrei Zhukov, the principal investigator for ASPIICS at the Royal Observatory of Belgium. "The difference between those is only the exposure time, which determines how long the coronagraph's aperture is exposed to light. Combining the three images gives us the full view of the corona."
"Our 'artificial eclipse' images are comparable with those taken during a natural eclipse," Zhukov explained. "The difference is that we can create our eclipse once every 19.6-hour orbit, while total solar eclipses only occur naturally around once, very rarely twice a year. On top of that, natural total eclipses only last a few minutes, while Proba-3 can hold its artificial eclipse for up to 6 hours.”
This artist's impression shows the Proba-3 Occulter blocking the Sun's disk so that the Coronagraph can image the space around the Sun. (ESA)
At the moment, Proba-3 is still receiving guidance from ESA operators on the ground, so that the two spacecraft continue to fly in perfect formation. However, the mission team's goal is to get the two doing this precision flying all on their own. Once that happens, they can leave the pair to send back new observations after each orbit.
The data returned by the mission will not only help researchers solve the mysteries of the corona's extreme temperatures, but it will also help space weather scientists, as well. The images returned by Proba-3 can act as an important tool to verify their computer models of the corona, which are used to forecast the impacts of solar activity here on Earth.
Thus, as Proba-3 continues to send back data, this could improve our ability to forecast auroras or even the potential disruptions to satellites and power grids that can result from extreme space weather.