European Space Agency's Proba-3 Achieves Historic Artificial Solar Eclipse

On June 16, 2025, the European Space Agency (ESA) unveiled the first images captured from its Proba-3 mission, which successfully demonstrated an artificial solar eclipse. This groundbreaking achievement marks a significant milestone in solar research, as it enables scientists to study the sun's elusive corona without relying on the sporadic occurrence of natural solar eclipses.

The Proba-3 mission utilizes a unique formation flying technique involving two satellites: the Coronagraph satellite and the Occulter satellite. Launched on December 5, 2024, from India’s Satish Dhawan Space Centre, the satellites operate in a precision formation, with the Occulter blocking the sun's direct light to allow the Coronagraph to capture images of the corona, which is the sun's outer atmosphere.

According to Andrei Zhukov, Principal Investigator for the Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (ASPIICS) at the Royal Observatory of Belgium, this innovative approach offers a new avenue for solar research. “The corona is not only visually stunning; it's a laboratory for plasma physics and the main source of space weather,” Zhukov stated at the Solar Eclipse Conference in Leuven, Belgium.

Historically, total solar eclipses occur approximately 14 times every 18 years, yet they are dependent on specific geographical locations, making them rare events. NASA has indicated that a total solar eclipse can occur only once every 366 years at any given location. Thus, the Proba-3 mission opens new possibilities, allowing researchers to generate over 1,000 hours of coronagraph images throughout its two-year mission.

The first images, which were produced during a successful formation flying demonstration on May 23, 2025, reveal the sun's inner corona, showing remarkable features such as coronal loops and prominences. The solar corona typically reaches temperatures of up to two million degrees Fahrenheit, a phenomenon that remains largely unexplained in solar physics.

“The artificial eclipse images we have captured can be compared to those taken during natural eclipses, but with the advantage of being able to create our eclipse every 19.6 hours,” noted Damien Galano, Proba-3 mission manager. The ability to capture the corona with minimal stray light, as achieved by Proba-3, represents a significant technological advancement in space exploration.

The Proba-3 mission is not the first to attempt artificial solar eclipses; a joint mission between the United States and the Soviet Union in 1975, known as the Apollo-Soyuz Test Project, produced limited results due to environmental factors affecting image quality. However, Proba-3's state-of-the-art technology is set to revolutionize solar studies.

As this mission progresses, the ESA plans to maintain an open data policy, allowing researchers worldwide to access the uncalibrated data for their own analyses. This collaborative approach reflects a growing trend in space exploration where data sharing enhances collective scientific understanding.

In conclusion, the Proba-3 mission not only provides new insights into the sun's behavior and its impact on space weather but also represents a pivotal shift in how solar phenomena can be studied, potentially leading to advancements in our understanding of solar physics and its implications for technology on Earth. As astronomers and scientists eagerly await further data from this innovative mission, the implications for solar research and space weather prediction remain substantial.