On January 10, 2025, the European Space Agency (ESA) announced its ambitious Proba-3 mission, designed to create artificial solar eclipses lasting up to six hours. This innovative approach aims to enhance the study of the Sun's outer atmosphere, known as the corona.
The Proba-3 mission will utilize two satellites, Occulter and Coronagraph, which will operate in precise formation approximately 500 feet apart. This configuration allows the Occulter to block sunlight, creating a shadow for the Coronagraph to observe the corona.
The primary objective is to gain insights into the corona, which is the source of solar wind and space weather phenomena. Understanding this region is crucial, as it can influence satellite operations and Earth's atmosphere through events like coronal mass ejections.
Notably, the corona reaches temperatures exceeding one million degrees Celsius, significantly hotter than the Sun's surface temperature of about 5,500 degrees Celsius. This counterintuitive temperature gradient raises important questions about solar physics.
Proba-3 aims to produce two artificial eclipses each week over the next two years, providing unprecedented opportunities for researchers to study the corona in detail. Lead researcher Andrei Zhukov emphasized the mission's transformative potential, stating, 'This really changes the game.'
The mission employs advanced technologies, including GPS, star trackers, lasers, and radio links, to maintain the precise positioning required for successful observations. This level of accuracy, described as 'the thickness of a fingernail' by ESA, marks a significant achievement in space exploration.