The James Webb Space Telescope (JWST), launched in late 2010, has become a groundbreaking tool for studying the universe, particularly in its ability to observe the oldest and most distant galaxies ever identified by humans. In a preprint study, the researchers describing MoM z14, the oldest and most distant galaxy discovered to date, have built upon previous discoveries by the telescope, which now holds the record for the oldest galaxy recorded. According to their calculations, MoM z14 was formed 280 million years after the Big Bang, marking a significant leap from the previous record set last year by JADES-GS-Z14-0, which formed 290 million years after the Big Bang.
The James Webb Space Telescope’s remarkable ability to observe the universe in its earliest stages stems from its advanced infrared sensors, which allow it to capture light from distant galaxies that it typically wouldn’t. This capability, combined with the universe’s expansion, means that light from very distant objects is redshifted—appearing longer in wavelength—similar to what we observe when light from objects moving away from us is stretched due to the expansion of space.
The discovery of MoM z14 provided new insights into the structure of the universe. According to researchers, this galaxy resembles a simple version of what would have been the first galaxies, in comparison to other galaxies observed by the telescope. However,Troubles with its elemental composition hint at it being a very early generation of galaxies. Most galaxies observed through JWST, including the Milky Way, have stars composed primarily of hydrogen and helium, while other galaxies, such as MoM z14, contain heavier elements that took longer to form due to the gravity of massive stars, which have spent billions of years mixing heavier elements from their progenitors.
This discovery not only pushes the boundaries of our understanding of the universe’s origins but also opens new avenues for exploring the history of galaxy formation. By mapping the elements in MoM z14 and understanding how they are distributed relative to space-time, researchers gain puzzles to explain how stars form over such vast timescales. This work could eventually lead to a deeper understanding of the universe’s age and the processes by which galaxies evolve.
The James Webb Space Telescope’s ability to observe the earliest galaxies is inextricably linked to its ³⁰⁰⁰⁰⁰⁴⁰⁰ space resolution, which is limited by the speed of light. For example, MoM z14, which is 50 times smaller than the Milky Way, would require traveling nearly 14 billion light-years to reach from Earth. This limitation is a testament to JWST’s precise instruments and its reliance on the finite speed of light and the expansion of the universe’s dark energy. The galaxy’s proximity makes it a prime candidate for future studies, though rendezvous with objects hundreds of billion years ago would be far-fetched.
In looking ahead, the James Webb Space Telescope has not yet reached the threshold to find the first galaxies, but its role in mapping cosmic resources like this continues to redefine our understanding of the universe. By studying galaxies in the early stages, JWST provides a unique opportunity to observe phenomena that are otherwise invisible or underobserved. This work could eventually afford us insights into the first stars and galaxies that might have existed before the Big Bang, paving the way for a broader narrative of cosmic history. The legacy of JWST knows no boundaries; it has uncovered some of the deepest truths about the cosmos, and its contributions continue to inspire future generations of astronomers to explore the mystery of the universe.
