NASA's James Webb Space Telescope has discovered four of the most distant galaxies ever observed, shedding light on the early Universe, as per a report from AFP.
IN SPACE - JULY 12: In this handout photo provided by NASA, NASA's James Webb Space Telescope reveals Stephans Quintet, a visual grouping of five galaxies, in a new light on July 12, 2022, in space. This enormous mosaic is Webb's largest image to date, covering about one-fifth of the Moons diameter. It contains over 150 million pixels and is constructed from almost 1,000 separate image files.
The Epoch of Reionization
According to two studies published in the Nature Astronomy journal, the galaxies were formed in the epoch of reionization, a period when the first stars are believed to have emerged, just 300 to 500 million years after the Big Bang more than 13 billion years ago when the Universe was merely two percent of its current age.
The most distant galaxy ever discovered by astronomers, known as JADES-GS-z13-0, was produced 320 million years after the Big Bang.
Infrared light detection by the James Webb Space Telescope is renowned for being extraordinarily sensitive. It can identify a variety of previously unseen galaxies, some of which can alter astronomers' perceptions of the early Universe.
Since the Universe is expanding, light from the farthest galaxies has been stretched and moved to the infrared spectrum by the time it reaches Earth.
This infrared light can only be detected by the NIRCam instrument on the Webb telescope, which makes it possible to find these previously unidentified galaxies.
All four galaxies are "very low in mass," weighing only a fraction of the Milky Way's estimated 1.5 trillion solar masses. Still, at the same time, they are very active in star formation in proportion to their mass.
The galaxies were producing stars at a startling rate for such a young stage of the Universe, roughly at the same rate as the Milky Way.
Read Also: NASA's James Webb Space Telescope Sees Shining Pearls, Diamonds in Previously Unseen Galaxies
Poor in Metals
The galaxies were also highly poor in metals, in accordance with the widely accepted theory of cosmology, which holds that the closer to the Big Bang, the less time there is for such metals to develop.
Pieter van Dokkum, an astronomer at Yale University who was not involved in the research, called the discovery of the distant galaxies a "technical tour de force."
Van Dokkum commented in Nature that the scientific frontier was advancing quickly, and only 300 million years of unexplored Universe history remains between these galaxies and the Big Bang.
The Webb telescope has detected other potential galaxies even closer to the Big Bang, but these have yet to be confirmed.
Earlier this year, the discovery of six massive galaxies between 500-700 million years after the Big Bang challenged the standard model of cosmology. These galaxies, also identified by the Webb telescope, were larger than initially expected so early after the Universe's birth. If verified, the standard model may need to be updated.
Related Article: NASA's James Webb Space Telescope Reveals Never-Before-Seen Details of the Early Universe
