Hubble Glimpses Merging Galaxy Clusters

Explore HubbleHubble Home OverviewAbout Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & BenefitsHubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts ScienceHubble Science Science Themes Science Highlights Science Behind Discoveries Universe Uncovered Hubble’s Partners in Science Hubble & Citizen Science AI & Hubble Science Explore the Night Sky ObservatoryHubble Observatory Hubble Design Mission Operations Science Operations Astronaut Missions to Hubble Hubble vs Webb TeamHubble Team Career Aspirations Hubble Astronauts MultimediaImages Videos Online Activities e-Books Sonifications Podcasts 3D Hubble Models Lithographs Fact Sheets Posters Hubble on the NASA App Glossary NewsHubble News Social Media Media Resources 35th Anniversary MoreOnline Activities 2 min read Hubble Glimpses Merging Galaxy Clusters This NASA Hubble Space Telescope image features a swarm of galaxies in the galaxy cluster called CL0016+1609 or MACS J0018.5+1626. NASA, ESA, H. Ebeling (University of Hawaii), D. Coe (STScI, ESA, JWST); Image Processing: G. Kober (NASA/Catholic University of America) This NASA Hubble Space Telescope image features a galaxy cluster, called CL0016+1609 or MACS J0018.5+1626, that is very bright at X-ray wavelengths and is one of the most extensively studied clusters at X-ray and radio wavelengths. The X-ray observations of this cluster revealed that it is two clusters merging along our line of sight. Researchers requested time to observe CL0016+1609 with Hubble’s Advanced Camera for Surveys because that data would help them accurately measure the cluster’s dark-matter distribution, which helps them study the merger and the role of CL0016+1609 in the large-scale structure of the universe. Hubble can’t directly see dark matter, but its infrared and visible light observations can detect dark matter’s gravitational lensing effects on the normal matter Hubble observes. The data in this image also includes observations with Hubble’s Wide Field Camera 3 taken as part of an observing program that obtained the first Hubble infrared images of 46 massive galaxy clusters and looked for distant galaxies gravitationally lensed by these clusters. Called RELICS (Reionization Lensing Cluster Survey), this survey found some 300 high-redshift candidate galaxies lensed by these clusters. You can see the faint vertical arc of one of these distant galaxies in the image above. Look for it just to the left of the large elliptical galaxies in the center of the image. Another brighter, though shorter arc is visible just above and to the right of the large elliptical galaxies in the center of the image. Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact: Claire Andreoli NASA’s Goddard Space Flight Center, Greenbelt, MD claire.andreoli@nasa.gov Share Details Last Updated Jun 18, 2026 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms Hubble Space Telescope Astrophysics Astrophysics Division Galaxies Galaxy clusters Goddard Space Flight Center The Universe Keep Exploring Discover More Topics From Hubble Hubble Space Telescope Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe. Hubble’s Galaxies Hubble Science Highlights Hubble Images The post Hubble Glimpses Merging Galaxy Clusters appeared first on NASA Science.