On December 5, two satellites took off from the east coast of India with a unique mission: to create artificial solar eclipses in space. Part of the mission Proba-3 of the European Space Agency (ESA), these revolutionary instruments are preparing to rewrite the way we observe the Sun. For the first time in history, it will be possible to thoroughly investigate the solar coronaa mysterious and fascinating region, which has always been a source of puzzles for scientists.
Despite being located right above the surface of the Sun, the solar corona has a temperature of millions of degrees, much higher than the 5,500°C of the visible core. An inexplicable phenomenon, which challenges the laws of physics as we know them. But that’s not all: the corona is also the point of origin of the phenomena of space weathersuch as solar flares and coronal mass ejections. Events that can disrupt communications, damage satellites and even disrupt electrical grids on Earth.
To observe this crucial region, scientists have so far had to rely on fleeting moments: total solar eclipses. These natural events, however, are rare and last only a few minutes, drastically limiting study opportunities. Proba-3 promises to change everything.
Two satellites, a perfect dance
The Proba-3 mission consists of two satellites: the Occulterwhich will bring a disk capable of blocking the light of the Sun, and the Coronagraphwhich will observe the crown from behind the created shadow. Separated in space by a distance of 144 meters, the two satellites must work in perfect synchrony, maintaining alignment with millimeter precision. A colossal undertaking, made possible thanks to highly advanced technologies: gyroscopes, star sensors and cold gas thrusters, as explained Daniel Seatonone of the main researchers involved in the project:
It’s like throwing a soccer ball from one side of a field to the other and having it land exactly on a dime.
The Artificial eclipses will not be visible from Earthbut they will be created in space, where they will last up to six hours. A huge advance compared to the few minutes allowed by natural eclipses. Thanks to these on-demand eclipses, scientists will be able to observe prolonged solar phenomena without having to chase the rare alignment between the Sun, Moon and Earth.
The collected images will be shared by ESA, offering new opportunities to better understand coronal processes and their influence on Earth.
If Proba-3 proves to be a success, this technology could find even more ambitious applications. For example, it could be used to block the light of other stars, paving the way for the discovery of distant planets and the exploration of star systems.
