ESA Satellites Create First Artificial Solar Eclipse In Orbit And The Photos Are Stunning
The European Space Agency (ESA) has achieved a rather unusual yet cool feat: successfully creating and maintaining artificial solar eclipses in space with its Proba-3 mission. This all comes down to precise formation maneuvering that enables the two-satellite system to create totality as needed, hence providing solar scientists with unprecedented, prolonged views of the Sun's enigmatic corona pretty much on-demand.
Launched in December last year, Proba-3 comprises two small spacecraft: the Occulter and the Coronagraph. The formation setup sees the Occulter, carrying a 1.4 meter-wide disk, precisely position itself 150 meters in front of the Coronagraph, effectively blocking out the Sun's direct light. This alignment casts a sharp shadow onto the Coronagraph's ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun) telescope, allowing for detailed observation of the faint outer atmosphere of our closest star.
Andrei Zhukov, lead scientist for ASPIICS at the Royal Observatory of Belgium proudly proclaims that "our 'artificial eclipse' images are comparable with those taken during a natural eclipse." The biggest difference, Zhukov adds, "is that we can create our eclipse once every 19.6-hour orbit, while total solar eclipses only occur naturally around once, very rarely twice a year. On top of that, natural total eclipses only last a few minutes, while Proba-3 can hold its artificial eclipse for up to 6 hours."
No doubt, Proba-3's capability to generate on-demand, extended periods of totality is a game-changer for solar physics. Still, aside from fundamental science, the mission holds significant implications for space weather as well. The corona is the source of the solar wind and coronal mass ejections (CMEs)—massive bursts of plasma and magnetic fields that can disrupt satellites, power grids, and communications on Earth. By providing prolonged observations of these phenomena, Proba-3 will enhance our ability to predict and mitigate the impact of solar storms.
The success of Proba-3 is a testament to cutting-edge technology used for precise formation "flying," even if the crafts are still in early commissioning phase. The two satellites maintain their millimeter-level relative positions autonomously, utilizing GPS, star trackers, lasers, and radio links. If this two-year mission brings more successes, it's possible that we may see similar, longer-term missions or even the possibility of multiple small spacecraft collaborating as a single, virtual giant instrument.
Photo credits: European Space Agency
