On August 12, 2026, the Moon will pass directly between the Sun and Earth, plunging parts of Greenland, Iceland, Spain and Portugal into darkness during a total solar eclipse. For up to a little over two minutes, daylight will fade to twilight and the Sun's outer atmosphere, known as the solar corona, will become visible to the naked eye, according to the European Space Agency. To get ahead of that brief window, ESA has spent recent days using an artificial eclipse-making satellite and a specially positioned spacecraft to forecast exactly what skywatchers and scientists will see.
Total solar eclipses are prized by scientists because they are the only natural events that fully expose the corona, the region where space weather is born. It is inside the corona that the solar wind accelerates before racing through the solar system, and where coronal mass ejections erupt outward, according to ESA. Those eruptions can disrupt satellite networks, communication systems and power grids on Earth, making the corona far more than a scientific curiosity.
The problem, ESA notes, is that natural total eclipses happen only about once, and rarely twice, a year, in different locations across the globe, and each one lasts just minutes. That leaves researchers with almost no time to study the corona directly from the ground. To get around this limitation, ESA built Proba-3, a mission it describes as an eclipse-maker on demand.
How Proba-3 Fakes an Eclipse
Proba-3 is not a single spacecraft but a pair flying in tight formation 150 meters apart, operating autonomously as though they were one instrument, according to ESA. One satellite, the Occulter, plays the role of the Moon, blocking out the Sun's disc. The second, the Coronagraph spacecraft, sits in the shadow the Occulter casts and uses its onboard instrument, called ASPIICS, to photograph the corona for hours at a stretch rather than the few fleeting minutes nature allows.
Andrei Zhukov, principal investigator for the ASPIICS instrument at the Royal Observatory of Belgium, said the mission recently produced its 62nd artificial eclipse since beginning normal operations. What made that particular observation notable, Zhukov said, is its timing: it was captured roughly two weeks before the natural eclipse expected on August 12. Because the Sun takes about two weeks to rotate halfway around its axis, flipping that image horizontally effectively previews what the corona should look like from Earth during the real eclipse, since the corona's large-scale structure tends not to change much over that span, Zhukov explained.
Most ground- and space-based coronagraphs, ESA notes, can reliably capture the outer corona but struggle to image the region closer to the Sun's surface, right where it transitions into the visible corona. Proba-3 was designed specifically to close that observational gap.
Solar Orbiter's Vantage Point
Proba-3 is not working alone. In the days before the eclipse, the ESA-led Solar Orbiter mission has been running a dedicated observation campaign with its suite of remote-sensing instruments. Because eclipses reveal coronal structures shaped by the Sun's magnetic field, they offer scientists a rare chance to check whether their computer models of that magnetic environment are actually correct.
"A total solar eclipse lets us verify that our models are correct by comparing forecasts with actual observations," said Jorge Amaya, ESA's Space Weather Modelling Coordinator.
Most solar observations come from instruments near Earth, which only offer a partial view of a vast, three-dimensional system. Solar Orbiter, however, travels a different path around the Sun than other observatories, and at the time of ESA's report was facing the side of the Sun that will soon rotate into view from Earth. That positioning let scientists on the ground decide in advance which features to prioritize once the eclipse arrives.
Of particular value are magnetic maps, or magnetograms, of the Sun's visible surface recorded by Solar Orbiter's Polarimetric and Helioseismic Imager, known as PHI. Combined with the spacecraft's unusual viewing angle, that data gives modelers a fuller picture of the Sun's current magnetic field than they could get otherwise. ESA said PHI has already spotted a newly emerging active region on the Sun that is likely to shape how the corona appears during the August 12 eclipse, a detection ESA says would not have been possible without Solar Orbiter's unique location.
"The magnetic field lines that we see in simulations are like hairs in a fuzz ball," said Amaya. "Observing the Sun from multiple viewpoints allows us to determine their orientation in three dimensions. That is the key to dramatically improving forecasts of how solar activity will affect our technology."
ESA also says Solar Orbiter's current vantage point offers a preview of what its future space weather forecasting mission, Vigil, will eventually deliver on a continuous basis. Vigil, planned for launch in 2031, is designed to trail Earth in orbit and provide near real-time observations of the side of the Sun that is otherwise hidden from direct view until it rotates toward our planet.
"With Proba-3 and Solar Orbiter, we have an unprecedented view of our star," said Miho Janvier, ESA project scientist for both missions. "Both missions are contributing to our understanding of the Sun, from its surface to its extended atmosphere. The upcoming total solar eclipse offers a chance to see how this knowledge comes together, comparing observations with modelling."
Beyond its own satellites, ESA's Solar Orbiter team has been feeding its data to Predictive Science Inc., a research group that produces detailed forecasts of what the Sun's corona should look like during major eclipses, publishing its projections online ahead of the event. For scientists, the exercise is as much about testing prediction models against reality as it is about the eclipse itself. When the Moon finally does slide across the Sun on August 12 over Greenland, Iceland, Spain and Portugal, researchers will be watching not just the spectacle overhead but also how closely their forecasts, built from weeks of satellite data and artificial eclipses, actually matched what nature delivered.
