Euclid's Exoplanet Revolution
Euclid Telescope Captures Record-Breaking Image of Milky Way's Central Bulge, Revolutionizing Exoplanet Science
Key Points
Euclid captured the galactic bulge from about 26,000 light-years away, viewing it through the foreground of dust and the Milky Way’s spiral arms, which is why the image also reveals dark dust clouds and hints of active star formation.
The mosaic is a nine-pointing composite, with each field covering an area larger than the Moon; the original image was captured in black and white and later colorized using observations from the Canada-France-Hawaii Telescope.
The image includes 51 known planetary systems and underscores Euclid’s utility for exoplanet science via microlensing by resolving individual stars in crowded regions, enabling mass measurements of planets in or beyond our Solar System.
Experts predict a potential explosion in exoplanet discoveries, with one scientist suggesting the field could grow from around 6,000 known exoplanets to more than 100,000 across the galaxy as a result of Euclid’s capabilities.
The European Space Agency's Euclid telescope has captured the largest and most detailed image ever taken of the Milky Way's heart — a stunning mosaic of more than 60 million stars packed into the galaxy's central bulge. ESA released the image on June 24, 2025, as part of its Quick Data Release 2, calling it a milestone for both astronomy and the search for worlds beyond our Solar System.
The image was taken on March 23, 2025, over just 26 hours — a feat that would have taken ground-based observatories like Keck roughly 2,000 hours to replicate, according to IFLScience. Scientists say it could transform how we find and study exoplanets, potentially growing the known count from about 6,000 to more than 100,000.
Nine Pointings, 60 Million Stars, One Historic Mosaic
Euclid's visible-light camera stitched together nine separate fields of view to build the mosaic. Each single pointing covers an area larger than the full Moon — and 270 times larger than Hubble's field of view, ESA noted. The telescope observed from about 26,000 light-years away, looking through layers of dust and spiral arms to reach the galaxy's crowded core.
The original image was captured in black and white. Scientists then added color using data from the Canada-France-Hawaii Telescope. Lead image processor Jean-Charles Cuillandre of CEA Paris-Saclay said: "Now we've decided to point Euclid at the brightest area of the sky — and it works superbly, it's extraordinary." The mosaic reveals dense dust clouds and active star-forming regions alongside individual stars that were previously impossible to separate.
51 Known Planetary Systems and a New Exoplanet Gold Rush
The image already contains 51 known planetary systems. Scientists plan to use a method called microlensing to find many more. Microlensing works when a foreground star's gravity bends and magnifies light from a star behind it, briefly making it brighter. If the foreground star has a planet, it leaves a detectable signal. It is the only method that can find planets thousands of light-years away near the galactic center, according to The Planetary Society.
Dr. Eamonn Kerins of the University of Manchester, co-lead of the Euclid Exoplanet Science Working Group, said the release "fires the starting pistol in a new age of exoplanet discovery." He predicts scientists will go "from knowing about 6,000 exoplanets to finding more than 100,000," according to The Guardian. These would include many cold planets — worlds orbiting far from their stars — that other telescopes like Kepler and TESS routinely miss.
Euclid's Position in Space Makes the Difference
Ground telescopes struggle in the galactic bulge. Earth's atmosphere blurs starlight, making it nearly impossible to separate individual stars in such a crowded field. Euclid sits at the Sun-Earth L2 Lagrange point, about 930,000 miles from Earth. There, it faces no atmospheric interference, giving it a sharp 0.1 arcsecond resolution, according to Live Science.
The mission launched in July 2023 on a SpaceX Falcon 9 rocket. Its early months were troubled — cosmic rays knocked out a guidance sensor, and water vapor froze on its mirrors. Routine science operations only began in February 2024. The galactic bulge survey was originally classified as "ancillary" science, secondary to Euclid's main goal of mapping dark matter and dark energy. Its success marks a major upgrade in how the mission is viewed, CBS News reported.
Euclid Sets the Stage for NASA's Roman Telescope
The new data is more than a snapshot — it is a reference map. NASA's Nancy Grace Roman Space Telescope, set to launch around 2027, will observe the same region looking for microlensing events. By comparing Roman's future data with Euclid's current images, scientists can measure planetary masses directly. That comparison method works best when the two observations are years apart, according to IFLScience.
Roman has a larger 2.4-meter mirror and will observe in near-infrared, likely finding more planets overall. But Euclid's visible-light mosaic is now the indispensable starting point. Jean-Philippe Beaulieu of the Institut d'Astrophysique de Paris, who first pushed for the bulge survey, said the image already includes 51 known planetary systems and stressed: "To catch microlensing, you need to observe parts of the sky that are crowded with stars." The €1.4 billion Euclid mission is now delivering science its designers never fully anticipated, according to University of Manchester.
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