Euclid Telescope Captures 60 Million Stars at Galaxy’s Heart

The European Space Agency has unveiled the largest and most detailed visible-light photograph ever taken of the centre of the Milky Way — a six-gigapixel mosaic containing more than 60 million stars, captured by the Euclid space telescope in just 26 hours of observations. Released on June 24, 2026, the image offers an unprecedented glimpse into the galactic bulge, the densely packed core of our galaxy located approximately 26,000 light-years from Earth, and marks the beginning of a transformative era in exoplanet science.

A New Window Into the Galactic Core

The image, taken on March 23, 2025, is a mosaic of nine separate “pointings” from Euclid’s visible-light camera (VIS). Each pointing covers an area of the sky larger than the full Moon, and the combined mosaic spans a region 270 times larger than the field of view of the Hubble Space Telescope. To observe the same area from the ground, the Keck Observatory in Hawaii would need approximately 2,000 hours — Euclid accomplished it in just over a day.

According to the European Space Agency, Euclid’s visible-light camera is sensitive enough to distinguish individual stars in the super-crowded galactic bulge without being blinded — a rare capability that is crucial for the scientific purpose behind the image.

“We decided to point Euclid at the brightest part of the sky. It works fantastically, it’s absolutely extraordinary,” said Jean-Charles Cuillandre, a French astronomer and Euclid mission collaborator, as reported by Het Laatste Nieuws.

A Revolution in Exoplanet Hunting

Beyond its stunning visual impact, the image serves a critical scientific purpose: enabling astronomers to discover and measure the mass of exoplanets using a technique called gravitational microlensing. This phenomenon occurs when two stars align perfectly from Earth’s perspective — the gravity of the foreground star bends and magnifies the light of the background star. If a planet orbits the foreground star, its gravity creates an additional, tiny distortion in the light curve, revealing the planet’s presence and allowing astronomers to calculate its mass.

“During the last twenty years, almost 300 exoplanets have been discovered using this technique, all with ground-based telescopes and all towards the centre of our galaxy,” said Jean-Philippe Beaulieu of the Institut d’Astrophysique de Paris and the University of Tasmania, who originally proposed Euclid’s galactic bulge survey. “This image from Euclid includes 51 known planetary systems — and it will assist in studying many more that will be found.”

The Guardian quoted Dr. Eamonn Kerins, an astrophysicist at the University of Manchester’s Jodrell Bank Centre for Astrophysics, who described the data as firing “the starting pistol in a new age of exoplanet discovery, where we go from knowing about 6,000 exoplanets to finding more than 100,000 across the galaxy.”

A Time Capsule for Future Discoveries

One of the most remarkable aspects of Euclid’s achievement is that the image serves as a time-domain baseline. Because Euclid captured the stars before they align for microlensing events, astronomers can now measure stellar motions over time and confirm exoplanet masses when future telescopes detect microlensing events.

“In 24 hours, Euclid has already captured the stars involved in all the future microlensing events that the Roman space telescope will detect, but before the stars and planets involved have aligned,” said Natalia Rektsini of the Institut d’Astrophysique de Paris, who led the release of the galactic bulge survey data. “Since Euclid can clearly separate individual stars, one can then measure how fast they move over time and use that information to confirm the existence of a planet and determine its mass.”

NASA’s Nancy Grace Roman Space Telescope, scheduled for launch in August 2026, will repeatedly observe the same region as part of its Galactic Bulge Time-Domain Survey. Euclid’s data will serve as an essential reference point, enabling measurements with up to three times better precision than previously possible.

Icy Worlds and the Promise of What Lies Ahead

Microlensing is uniquely suited to finding cold, icy planets that other detection methods miss. Two known cold exoplanets already appear in Euclid’s data: OGLE-2005-BLG-390Lb, an icy world discovered 20 years ago that scientists describe as “a bit like Hoth from Star Wars,” and OGLE-2013-BLG-341Lb, a rare system consisting of two stars and one planet.

“Visually, it has the emotional impact of a great astronomical artwork. Scientifically, every star in the frame is data,” Dan Zafra, co-founder of Capture the Atlas, told Forbes. “It is beautiful at first glance, but the longer you look at it, the more you realize that its real value is not only aesthetic. It is a tool for understanding our galaxy and the planets hidden within it.”

What’s Next

Euclid, launched in July 2023 and operating from the L2 Lagrange point 1.5 million kilometres from Earth, is primarily designed to map the dark universe — dark matter and dark energy — by observing billions of galaxies over a six-year mission. This detour to study the galactic bulge demonstrates the telescope’s versatility and the ingenuity of the Euclid Consortium, which includes over 2,000 scientists from 300 institutes across Europe, the United States, Canada, and Japan.

Valeria Pettorino, Euclid Project Scientist at ESA, noted: “This result shows what a relatively small, dedicated team can achieve within a large international mission.”

With the Roman Space Telescope’s launch just weeks away and Euclid continuing its survey, the coming years promise an explosion in our knowledge of exoplanets — from the roughly 6,000 known today to potentially more than 100,000. The heart of the Milky Way, it turns out, holds secrets we are only beginning to uncover.