The mystery of solar eclipses has fascinated humanity for generations , but now, thanks to an unprecedented technological advance, scientists have managed to reproduce this phenomenon on demand from thousands of kilometers above the Earth's surface. The European Space Agency (ESA) was responsible for carrying out the first artificial solar eclipse in orbit , achieving a historic milestone in astronomical observation and the study of the Sun.
This achievement comes from the Proba-3 mission , composed of two small satellites—Occulter and Coronagraph— flying in formation just 150 meters apart . Using European navigation, positioning, and control technologies, both satellites manage to remain perfectly aligned with an accuracy of less than one millimeter, something essential to simulate the effect of the Moon blocking the Sun during a total eclipse.
How is an artificial solar eclipse generated?
The key to the mission lies in the function of each satellite: the Occulter acts as an 'artificial moon,' blocking the intense sunlight with a 1,4-meter-diameter disk. The shadow created—just 8 centimeters wide—falls precisely on the second satellite, the Coronagraph , which carries the sophisticated ASPIICS instrument. This specialized telescope obtains images of the solar corona, the outermost and most mysterious layer of the Sun's atmosphere, allowing it to be studied in detail without the blinding veil of the solar disk.
Unpublished images and what they reveal about the Sun
The first images obtained by Proba-3 are revolutionizing how we view the solar corona . These images are achieved by combining three different exposures, each with a specific duration, resulting in a complete and detailed view that is usually only visible for brief moments during natural eclipses.
The images reveal spectacular details in various colors , reflecting different elements and temperatures: dark green tones indicate the presence of ultra-hot iron, yellow highlights solar prominences—giant loops of plasma—and violet reveals structures called coronal streamers. Thanks to the mission's design, these observations are achieved without atmospheric interference and with unprecedented quality.
The solar corona is one of the Sun's most enigmatic regions: although it is farther from the core, it reaches temperatures of up to 2 million degrees Celsius , much higher than the visible surface of the star. Understanding why this happens, and how coronal mass ejections affect space weather and telecommunications on Earth, is one of the key objectives of the Proba-3 mission.
Technological innovation and international cooperation
Behind this project is a European collaboration involving more than 29 companies from 14 different countries . Their contributions range from solar tracking sensors to light detectors produced by European startups, as well as a fully developed control software to orchestrate the precise orbital choreography required by the mission. The consortium is led by the ESA and includes the direct participation of the Spanish company Sener, among other technology firms.
In addition to cameras, Proba-3 is equipped with instruments that measure solar energy and detect energetic particles , thus expanding the mission's scientific scope. The entire process takes place in an elliptical orbit ranging from 600 to 60.000 kilometers in altitude and is primarily conducted near apogee, when the gravitational influence and friction of Earth's atmosphere are minimal, allowing for fuel savings and maintaining alignment for hours.
A new paradigm for solar science
The Proba-3 mission represents a paradigm shift: it allows the scientific community to replicate and study solar eclipses at will , opening the door to experiments and analyses previously impossible. Among those who will benefit most are researchers investigating space weather, plasma physics, and the Sun's influence on Earth.
The ESA applies an open data policy : anyone can access the uncalibrated images and measurements, facilitating collaborative work and participation from scientists, enthusiasts, and amateur astronomers alike. It is expected that over the two-year mission will yield more than 1.000 hours of coronal imaging . Once their fuel is exhausted, the Proba-3 satellites will disintegrate upon re-entry into Earth's atmosphere.