The European Space Agency’s Proba‑3 mission has successfully produced the world’s first artificial solar eclipses by flying two satellites in millimeter-precise formation—one acting as an “occulter” to block the Sun, and the other as a “coronagraph” to image the solar corona—on demand
🔬 Mission Mechanics
- Precision formation flying: The pair maintains a rigid 150 m (492 ft) separation with millimeter accuracy, using autonomous GPS, star trackers, lasers, and radio links
- Orbit & cadence: Flying in a highly elliptical ~20-hour orbit (600 km to 60,000 km from Earth), the satellites can simulate eclipses for up to six hours each orbit—about twice a week, aiming for 200 eclipses over two years, totaling ~1,000 hours of “totality”
🧭 Scientific Significance
- Unprecedented corona imaging: For the first time, scientists can observe the innermost solar corona continuously for hours—something natural eclipses cannot provide
- Studying coronal heating & solar wind: Data gathered may unlock why the corona is millions of degrees hotter than the Sun’s surface and how solar wind accelerates—and, crucially, help forecast space weather that affects Earth
🚀 Milestones & Early Results
- First eclipse on first try: Since March, ten successful eclipses have been conducted during checks, with the longest lasting five hours
- Raising the bar in space formation flying, this is the first dual-satellite coronagraph in space—a major advance over previous single-craft missions
🔭 What’s Next?
- Start full science operations in July 2025: Eclipse frequency will increase to twice per week, with over 1,000 hours of study time expected
- Scientific payoffs ahead: Continuous and high-resolution observations will help decode solar dynamics—critical for predicting geomagnetic storms that can disrupt Earth’s tech systems
🌎 Why It Matters
- Game-changer for solar science: With hours-long artificial eclipses, Proba‑3 gives researchers far more time to study the Sun’s elusive corona.
- Paves way for future missions: Demonstrates advanced formation-flying that could be used for next-gen telescopes, precise Earth observation, and deep-space science.
- Improves space weather prediction: Better forecasting can protect satellites, power grids, communications, and airlines from solar storms.
✅ Final Take
ESA’s Proba‑3 artificial solar eclipse mission marks a quantum leap in how we observe the Sun. By creating controlled eclipses in space, the mission enables prolonged study of the corona—potentially solving long-standing mysteries about solar heating and wind, and boosting our ability to predict cosmic weather that impacts life on Earth.
