In a groundbreaking discovery, the James Webb Space Telescope (JWST) has confirmed the existence of the second- and fourth-most distant galaxies ever observed. These ancient galaxies, located in Pandora's Cluster (Abell 2744), offer unique insights into the early universe and challenge our understanding of galaxy formation.

The findings, published in the Astrophysical Journal Letters, were made by an international team of researchers led by Penn State University, using data from JWST's Near-Infrared Camera (NIRCam). By analyzing spectroscopic data collected by JWST, the team was able to confirm the distance and properties of these incredibly distant galaxies.

The two galaxies, labeled UNCOVER z-13 and UNCOVER z-12, were detected in a deep field image taken by JWST in 2022. Unlike other galaxies observed at this extreme distance, these ancient galaxies appear larger and have distinct shapes. One appears elongated, resembling a peanut, while the other has a fluffy ball-like appearance.

"These early galaxies are showing signs of being very different from one another, which is quite intriguing. It raises questions about how stars formed and what happened to them after they formed," explained Bingjie Wang, a postdoctoral scholar at Penn State and a member of the JWST UNCOVER team.

Remarkably, the two galaxies discovered are considerably larger than the three previously located at similar distances. One of the galaxies is estimated to be at least six times larger than any previously known galaxies at these extreme distances. This challenges the existing understanding that the early universe was compressed and suggests that galaxy formation was more diverse than previously thought.

The light observed from these galaxies has traveled about 13.4 billion light years to reach JWST, but due to the expansion of the universe, they are currently estimated to be approximately 33 billion light years away from Earth. Their immense distance allows scientists to peer into the past, offering valuable information about the early universe.

"These early galaxies are like beacons, shedding light on the exotic physics that governed the galaxies near the cosmic dawn," said Joel Leja, an assistant professor of astronomy and astrophysics at Penn State and a member of the UNCOVER team.

The properties of these ancient galaxies provide valuable insights into the early universe. The researchers found that these galaxies were young, rapidly growing, and actively forming stars. It is believed that these galaxies lack heavy elements like metals because they were some of the first factories to produce these elements through fusion.

The discovery of these two distant galaxies demonstrates the power of JWST's observations beyond what was previously detected. While the team acknowledges that their window of observation was limited, they remain hopeful that JWST's infrared instruments can detect even more distant galaxies if they exist.

The research was made possible through a successful proposal submitted to NASA, allowing JWST to conduct observations during its first year of science operations. The team faced challenges and time constraints but successfully coordinated JWST's observations, leading to this groundbreaking discovery.

The confirmation of these second- and fourth-most distant galaxies highlights the crucial role of JWST in unraveling the mysteries of the early universe. As scientists continue to explore Pandora's Cluster and other regions of space, new and exciting discoveries are expected to reshape our understanding of galaxy formation and the origins of our universe.