In a revolutionary move that is bound to “transform solar observing”, the European Space Agency’s (ESA) Proba-3 has already imaged the first artificial solar eclipse in space after two of the satellites launched as a pair of spacecraft on an Indian PSLV-XL launch rocket in December 2024 were manoeuvred as a pair and made their inaugural Sun block on May 23.
The engineered eclipse images were obtained with unprecedented millimetre-precision accuracy, replicating the sun-blotted view of a natural solar eclipse, which is exceedingly uncommon. Natural eclipses happen only once every 366 years in any geographic region, making the view of the sun’s hazy outer atmosphere, or corona, a scarce and thrilling event.
ESA’s Proba-3 Revolutionizes Solar Study with Artificial Eclipse Tech
As per an ESA report, the mission uses a pair of satellites: one acts as an artificial moon blocking the sun, while the other captures images using a telescope called ASPIICS. This setup acts like a spaceborne coronagraph, far surpassing ground-based models hampered by Earth’s atmosphere.
“Current coronagraphs are no match for Proba-3,” noted Jorge Amaya, ESA’s space weather modelling coordinator. The corona, a million times dimmer than the sun’s disc, is vital for understanding solar wind and space weather that can affect Earth’s power grids and satellite systems.
Proba-3 imaging of solar phenomena, including prominences and coronal mass ejections, has already provided fine solar structures down to the inner face of the corona. The imaging can be repeated every 19.6 hours, which is even faster than waiting for what nature intended.
The spacecraft, in a precise elliptical orbit, acts as a large coronagraph at a distance of 60,000 km from Earth with the required self-alignment accuracy of 1 mm. The data, which will be processed by the Royal Observatory, will be free for scientists around the world.
Space-based artificial eclipses get around nature’s limits, enabling solar scientists to gain access to the star that has made life on Earth possible and allowed humanity to contemplate its place in the cosmos, ushering in a new era of solar physics.
