The James Webb Space Telescope has made a groundbreaking discovery, identifying a group of five galaxies that may be among the oldest ever observed in the universe. These candidates, located 13.6 billion light-years away, are believed to have formed just 200 million years after the Big Bang.
If confirmed, this finding would shatter the previous record held by the galaxy JADES-GS-z14-0, which was identified approximately 280 million years post-Big Bang. This discovery signifies a monumental advancement in humanity's ability to study the cosmic dawn, a period that was previously beyond our reach.
The observations conducted with Webb are notable not only for their ability to probe the universe's early moments but also for their focus on specific regions of the sky where gravitational lenses amplify the light from distant galaxies.
“It is astonishing how we are observing the early stages of galaxy formation. These galaxies are literally assembling before our eyes,” explained Lamiya Mowla, a co-author of the study and professor at Wellesley College in Massachusetts. According to the scientific team, these galaxies present a unique opportunity to analyze how the structural formation of the universe began.
The research team utilized the gravitational lensing effect caused by the galaxy Abell S1063 to observe these galaxies. This phenomenon, predicted by Einstein's general theory of relativity, enables massive objects like galaxies to warp space-time and amplify the light from objects located behind them.
This effect, combined with Webb's infrared sensitivity, made it possible to observe the oldest galaxies detected to date, which would otherwise be invisible even to the most advanced telescopes.
According to the study's authors, these galaxies could represent the first generation of cosmic structures, formed from primordial fluctuations in the cosmic microwave background.
These fluctuations led to the formation of the first clumps of matter that collapsed under their own gravity to create the first stars and galaxies. “With only 150 million years to form, these galaxies pose a challenge to the current models of galaxy formation,” noted Hakim Atek, another co-author.
While the James Webb Telescope has pushed the boundaries of astronomical observation further than ever before, even this impressive instrument has limitations. Detecting even older galaxies would require observation times that could exceed 450 hours, a challenging prospect given the number of ongoing projects.
“The GLIMPSE program has already pushed the telescope to its maximum capabilities,” indicated Vasily Kokorev, the principal investigator of the project and a scientist at the University of Texas.
However, the detection of five galaxies in the same region of the sky suggests that many more may exist in that area, waiting to be uncovered with future technologies.
The James Webb Space Telescope is the most advanced space observatory ever built. Launched on December 25, 2021, it orbits the Sun at a distance of 1.5 million kilometers from Earth. This telescope was specifically designed to observe the first galaxies formed after the Big Bang and to explore the atmospheres of planets in search of signs of life.
Equipped with state-of-the-art infrared technology, Webb is a collaborative effort between NASA, ESA, and CSA, marking a significant milestone in cosmic exploration.