Warped Space
ESA / Hubble & NASA, M. Postman, P. Kelly
Day 21 of the 2025 Space Telescope Advent Calendar: Warped Space. This Hubble view of Galaxy Cluster Abell 209, about 2.8 billion light-years away, shows more than 100 galaxies. The incredible mass of the galaxies together warps and magnifies images of background galaxies and stars in a process called gravitational lensing, which can be seen in the stretched and smeared clumps toward the center of the image.
See the full advent calendar here, where a new image will be revealed each day until December 25.