The James Webb Space Telescope (JWST) has detected five galaxies that likely formed just 200 million years after the Big Bang, marking them as some of the earliest known galaxies. Researchers announced their findings on November 26, 2024, in a preprint database, although the results have yet to undergo peer review.
If subsequent observations confirm the scientists' hypothesis, these ancient galaxies could provide crucial insights into the formation of galaxies and the evolution of matter in the universe.
According to the researchers, these first galaxies had remained beyond the reach of previous observations for decades. The JWST has significantly advanced the ability to study these early cosmic structures.
Previously, cosmologists estimated that the first star clusters began merging and forming galaxies a few hundred million years after the Big Bang. Current theories suggest that around 1-2 billion years after the universe's inception, early protogalaxies reached a stage of development, evolving into dwarf galaxies that eventually merged into larger galaxies, like our own.
Determining the exact timing and pace of these processes remains challenging due to the faint light from these galaxies and the stretching of their wavelengths caused by the expansion of the universe.
Unlike its predecessor, the Hubble Space Telescope, JWST is capable of detecting light in the infrared spectrum, allowing it to observe the earliest stages of the universe's development.