How two satellites will create a man-made solar eclipse in deep space
The European Space Agency is launching a pair of satellites designed to fly in perfect formation. By casting a shadow from one onto the other, they will create a sustained artificial eclipse to reveal the Sun's faint corona.
Launching this autumn, the Proba-3 mission marks the world's first precision formation flying experiment. The two satellites will maintain a distance of 144 meters, allowing them to block the Sun's brilliant face for up to six hours at a time. This setup mimics the effect of a natural eclipse, which is usually required to observe the Sun's corona—a region typically obscured like a firefly next to a bonfire.
Beyond its scientific goal of studying the solar atmosphere, the mission serves as a testbed for advanced guidance technologies. The ability to keep two independent platforms in such precise alignment is a critical demonstration for future space operations.
