Although the photograph itself is modern, it displays a landscape belonging to deep antiquity. This image, taken by the James Webb Space Telescope on July 3, was published by NASA and depicts the galaxy cluster MACS J0553.4-3342. The telescope's infrared camera (NIRCam) registered the image of this cluster in 2026, but the event itself occurred 4.4 billion years ago.
The first thing to understand is that light requires time to travel through space. Secondly, the JWST (short for James Webb) is capable of observing the most distant regions in deep space. Because of this, the telescope effectively functions as a kind of time machine.
Light travels at a constant speed of approximately 300,000 kilometers per second. This means that any image of an object in space reflects not its current state, but what it was when the light was emitted. Since James Webb is designed to observe extremely distant objects located billions of light-years from Earth, it captures rays of light that have traveled through space for billions of years. By registering this ancient luminosity, the telescope displays the Universe exactly as it was in the distant past.
Essentially, observing the depths of space through James Webb is equivalent to watching a recorded 'rewind' of the Universe's childhood. Thus, researchers can see stars and galaxies that formed shortly after the Big Bang. This capability is not unique to JWST; other telescopes, such as Hubble, have also studied the past of the cosmos and provided impressive old images. Nevertheless, James Webb has its own distinctive features.
To see this distant past, the telescope uses high-tech infrared sensors. The reason is as follows: over billions of years of travel, the light emitted by the first galaxies has undergone a phenomenon known as 'redshift,' caused by the continuous expansion of the fabric of space itself. This expansion has stretched visible and ultraviolet light, turning it into infrared light that is invisible to the human eye. By capturing this stretched infrared radiation, James Webb reveals the mysteries of the origin of the cosmos, acting as our cosmic archaeologist.
Another interesting point is that the farther a celestial body is from us, the longer it takes for its light to cross space and reach our eyes. Therefore, the light from your favorite constellation probably traveled millions of light-years to reach your field of view. Next time you look up at the starry sky, remember that you are observing a mosaic of ancient landscapes.
The process of galaxy nucleus formation has been recorded for the first time. At the center of many galaxies, including the Milky Way, there is a dense and compact structure of stars rotating around the center—the so-called nuclear disk. These disks are a common phenomenon in the Universe, but previously no one had seen how such a disk forms so early in cosmic history.
Astronomers from the University of Durham in the UK have discovered the most distant nuclear disk ever observed. It was found in a galaxy that existed only 4.5 billion years after the Big Bang. The research results were published in the Monthly Notices of the Royal Astronomical Society.
This discovery was made possible by the unprecedented sensitivity and resolution of the James Webb Space Telescope. By studying the galaxy CEERS-4031, researchers identified an active nuclear disk at its center, which continues to form new stars and grow. This disk has a radius of about one kiloparsec (approximately 3260 light-years) and possesses characteristics similar to nuclear disks in modern nearby galaxies: it is compact, rich in young stars, and shows clear signs of organized growth.
The formation of this disk did not happen spontaneously. Researchers determined that the cause was a stellar bar—an elongated structure of stars crossing the center of the galaxy, which is characteristic of spirals like the Milky Way. Such bars act as cosmic engines, directing gas and stars toward the center, thereby fueling the formation of new structures.
Although previous studies showed that stellar bars can form early in the Universe, none of them proved that they were already reshaping galaxies as early as demonstrated in this study. Zoe Le Conte, the lead author of the study, noted that this is a 'remarkable and unexpected discovery that will force astronomers to reconsider the understanding of galaxy evolution and the influence of stellar bars in the early Universe.'
This discovery calls into question established ideas about how galaxies evolve. The traditional model suggested that galaxies gradually acquired complex internal structures over billions of years. However, the results of this study show otherwise: galaxies did not reach their current appearance gradually, but matured rapidly, following evolutionary trajectories similar to modern galaxies much earlier than previously thought.
Le Conte added that 'the stunning images and innovative results from James Webb continue to show that mature galaxies exist much earlier than we previously thought.'
The significance of this discovery extends beyond just galaxy formation. Nuclear disks are considered reservoirs of gas that feed supermassive black holes at the centers of galaxies. The detection of such an ancient (and still active and growing) nuclear disk may help scientists understand how these black holes grew during a period of cosmic activity when the Universe formed stars and structures with much greater intensity than today.
The team plans follow-up observations to study the movement of stars and gas within the galaxy, which will be the next step in accurately confirming exactly how the disk formed and how effectively the bar moves matter to the center.
