The James Webb Space Telescope (JWST) has unveiled its largest-ever panorama of the early universe through the COSMOS-Web project, the telescope's most extensive observing program in its first year. This survey captured a patch of sky equivalent to three full moons side by side, stitching together over 10,000 exposures to reveal nearly 800,000 galaxies, many from the universe’s earliest eras. Released on June 5, 2025, this contiguous image, accompanied by a free, interactive catalog detailing each galaxy’s properties, offers unprecedented insights into the formation and evolution of galaxies over 12 billion years.
Here are some key details and the significance of this revelation:
- COSMOS-Web Program: The images were collected as part of COSMOS-Web, the largest observing program undertaken by the JWST in its first year. This program was allocated over 200 hours of observation time, the most for any project in the telescope's inaugural year.
- Vast Survey Area: The panorama surveyed a patch of sky equivalent to the width of three full moons placed side-by-side, representing the telescope's widest observation area to date.
- Immense Data: The survey stitched together more than 10,000 individual exposures, revealing nearly 800,000 galaxies, many of which shine from the universe's earliest eras.
- Largest Contiguous Image and Interactive Catalog: The team released the largest contiguous image ever captured by the JWST, along with a free, interactive catalog detailing the properties of each galaxy.
- Challenging Existing Theories: The abundance of galaxies found in the early universe is at the upper end of all predictions, and in some cases, the presence of surprisingly massive and well-structured galaxies (like Zhúlóng, a distant Milky Way "twin" discovered previously using JWST data) at much earlier times than expected is prompting astronomers to reassess how and when galaxies took shape after the Big Bang.
- Studying Galaxy Evolution and Reionization: This expansive view allows astronomers to not only catalog distant galaxies but also to study how their characteristics (size, shape, brightness) are shaped by their cosmic environments. A key science goal is to map the earliest structures during the Reionization Era (more than 13 billion years ago) when the first galaxies ignited and began clearing the thick hydrogen fog that blanketed the early cosmos.
- Open Science: The collaboration has made all imaging data and the galaxy catalog freely available to the global scientific community, promoting transparency and enabling further research.
This panorama is a significant leap forward in our understanding of how galaxies formed and evolved across 98% of cosmic time, providing a wealth of data for scientists worldwide.