The European Space Agency’s Euclid mission has produced the largest and most detailed visible-light image ever taken of the center of the Milky Way, showing more than 60 million stars in the galactic core. The observation was released this week and was taken on March 23, 2025, using nine separate pointings that together took about 26 hours.
Euclid was launched in July 2023 to investigate the universe’s “dark sector,” meaning dark matter and dark energy, and it began scientific observations in February 2024. Over its six-year mission, the telescope is expected to study the shapes, distances and motions of billions of galaxies as far as 10 billion light years away. Its visible-light camera is designed for that work, but it is also sensitive enough to distinguish individual stars in the crowded center of our own galaxy without being blinded.
That capability matters for microlensing, a technique used to find faint or invisible objects such as exoplanets and black holes by detecting temporary changes in brightness caused by gravity bending light. Dr. Jean-Philippe Beaulieu of the Institut d’Astrophysique de Paris and the University of Tasmania, who initiated Euclid’s galactic center survey, said the central regions of the sky are the best places to catch such events. He noted that in the past 20 years almost 300 exoplanets have been found this way from ground-based telescopes, all toward the Milky Way’s center, and said Euclid’s image includes 51 known planetary systems and will help identify many more.
The telescope’s images also serve as a reference for future searches. Dr. Natalia Rattenbury of the Institut d’Astrophysique de Paris said Euclid captured the stars involved in future microlensing events before those systems align, allowing scientists later to compare them with the earlier data. She added that because Euclid can separate individual stars, researchers can track their motion over time, confirm a planet’s existence and measure its mass, something impossible from a single snapshot alone. Dr. Valeria Pettorino, Euclid’s project scientist at ESA, said the image shows what “a relatively small and dedicated team” can achieve within a major international mission.
