Webb is NASA's largest and most powerful space science telescope.
Since it started sending data and pictures last year, NASA's James Webb Space Telescope (JWST), the most powerful space observatory ever built, has been sending an endless supply of information. Now, it has found the four most distant galaxies ever seen, one of which formed only 320 million years after the Big Bang, when the cosmos was still in its infancy.
By the time light from the most distant galaxies reaches Earth, it has been stretched by the expansion of the universe and shifted to the infrared region of the light spectrum.
The Webb telescope's NIRCam instrument has an unprecedented ability to detect this infrared light, allowing it to quickly spot a range of never-before-seen galaxies, some of which could reshape astronomers' understanding of the early universe.
In two studies published in the Nature Astronomy journal, astronomers revealed they have "unambiguously detected" the four most distant galaxies ever observed.
The galaxies date from 300 to 500 million years after the Big Bang, more than 13 billion years ago, when the universe was just two percent of its current age.
That means the galaxies are from what is called "the epoch of reionization," a period when the first stars are believed to have emerged. The epoch came directly after the cosmic dark ages brought about by the Big Bang.
This is not the first time James Webb's telescope has discovered something like this.
In February, the data obtained by the telescope revealed what appear to be six big galaxies as mature as our Milky Way, existing about 540 million to 770 million years after the explosive Big Bang that kicked off the universe 13.8 billion years ago. The universe was roughly 3 percent of its current age at the time.
These galaxies, one of which appears to have a mass rivalling our Milky Way but is 30 times more densely packed, seem to differ in fundamental ways from those populating the universe today.
Webb was launched in 2021 and began collecting data last year. The findings were based upon the first dataset released by NASA last July from Webb, a telescope boasting infrared-sensing instruments able to detect light from the most ancient stars and galaxies.
(With inputs from agencies)