The European Space Agency (ESA)'s Proba-3 mission has achieved a groundbreaking feat: creating the first artificial solar eclipse in space. This was accomplished by two satellites working in tandem, offering unprecedented detail of the Sun's corona.
Launched in December 2024, the mission comprises two satellites, separated by 150 meters. One satellite, the Occulter, features a 1.4-meter-wide carbon fiber disc to block the Sun's light for the second satellite, the Coronagraph, which is equipped with cameras and scientific instruments.
In March, the satellites autonomously aligned themselves for several hours, capturing multiple exposures of the solar eclipse. Scientists at ESA have assembled these images into a complete picture of the Sun's corona, the outermost layer of the Sun's atmosphere, which reaches temperatures of millions of degrees Celsius.
The Proba-3 mission will also observe the frequencies of light corresponding to specific elements in the corona, such as iron, which emits light from the hottest regions.
Furthermore, Proba-3 has demonstrated the solar corona in polarized white light, artificially colored in purple. This was achieved through a special technique that allows scientists to separate the polarized light of the corona from the light scattered by interplanetary dust.
These images were primarily for testing the functionality of Proba-3. When fully operational, the mission will capture an artificial solar eclipse image every 19.6 hours, including longer exposures of six hours.
This achievement will enhance our understanding of the physics of the solar corona and help us better understand the solar wind and coronal mass ejections, which impact space weather.