Thanks to the help of the “monster” galaxy cluster Pandora, the James Webb Space Telescope has captured images of two galaxies located 33 billion light-years away from Earth.
Even though it is the most powerful space telescope in the world, the “war god” James Webb, co-operated by NASA, ESA, and CSA (the space agencies of the United States, Europe, and Canada), does not have the capability to observe such distant objects.
However, by observing through the Pandora Cluster, also known as Abell 2744, a gigantic galaxy cluster 3.5 billion light-years away from Earth, astronomers from Pennsylvania, USA, discovered something miraculous.
UNCOVER-z12 and UNCOVER-z13 are two ancient galaxies recently discovered with the help of the Pandora Cluster.
Two ancient galaxies, one described as resembling a peanut and the other as a cotton ball, are nearly three times older than Earth.
They represent the oldest class of galaxies, the “children of the Big Bang”, with light streaming through a very thin layer of hydrogen gas that formed the primordial universe.
Scientists have yet to explain why these objects, located 33 billion light-years away from Earth, have different shapes despite being made from the same material in a chemically primitive universe.
They also exhibit a ghostly blood-red color, caused by the phenomenon known as “redshift”: Initially, these galaxies were not so far from Earth, but the universe has pushed them farther away during its expansion.
The red color is produced as a consequence of the Doppler effect, where spectral lines in visible light shift towards the red spectrum due to a decrease in electromagnetic wave frequency during this “runaway.” The redder the object, the faster and farther it is moving away from us.
Only three galaxies have been discovered at such great distances before, but these two newly found galaxies are particularly notable because they are much larger. The reason why such gigantic galaxies could form when the universe was just beginning remains a mystery.
The reason the James Webb was able to capture images of them at such a great distance is due to the Pandora Cluster acting as a “gravitational lens.”
This occurs when something extremely massive, with strong gravitational force, obstructs the line of sight from Earth to a very distant object. This gravitational force bends spacetime, causing light passing through it to behave like it is going through a magnifying glass, thereby enlarging the more distant object.
