Astronomers have uncovered dozens of small galaxies that played a crucial role in transforming the early universe into what we see today, thanks to data from NASA's James Webb Space Telescope.

Isak Wold, an assistant research scientist at Catholic University of America and NASA's Goddard Space Flight Center, highlighted the significant role these small galaxies played in producing ultraviolet light. Their analysis, ten times more sensitive than previous studies, revealed that these galaxies had the power to drive a cosmic renovation.

Wold presented his findings at the American Astronomical Society's meeting in Alaska, discussing how the study utilized imaging from Webb's NIRCam and NIRSpec instruments to identify these tiny yet powerful galaxies.

The galaxies were discovered as part of the UNCOVER observing program, focusing on the Abell 2744 galaxy cluster, also known as Pandora's cluster, located about 4 billion light-years away. The cluster's mass acted as a gravitational lens, enhancing Webb's ability to observe distant sources.

During the universe's early years, it was filled with neutral hydrogen gas, which has now been ionized. The process of reionization has long intrigued astronomers, who have debated whether big galaxies, small galaxies, or supermassive black holes were responsible. Webb was designed to address these questions.

Recent studies suggest that small galaxies with intense star formation may have played a significant role in this cosmic transformation. While rare today, these galaxies were abundant around 800 million years after the Big Bang, contributing to reionization.

The team identified 83 small starburst galaxies in Webb's images, representing a snapshot of the universe when it was 800 million years old. Further analysis of 20 of these galaxies using NIRSpec provided deeper insights into their properties.

These small galaxies, though numerous, are dwarfed by the Milky Way in terms of stellar mass. However, their unique characteristics and the use of gravitational lensing allowed astronomers to detect them.

If these low-mass starburst galaxies emit a significant amount of ultraviolet light, they could have been responsible for ionizing the universe's neutral hydrogen, driving the transition to its ionized state.

The James Webb Space Telescope continues to unravel mysteries in our universe, shedding light on our cosmic origins and the structures that define our place in the cosmos.