NASA’s James Webb Space Telescope has revealed the most distant galaxies ever discovered, some of which date back just 300 million years after the creation of the universe in the Big Bang, a time when the universe had only 2% of its size. his current age.
The primordial galaxies have been found by an international team of scientists responsible for the design of two of the JWST’s newest instruments. The first instrument, known as the Near Infrared Camera (NIRCam), has the task of observing a small portion of the night sky in the constellation Fornax.
Over the course of 10 days, NIRCam observed light from a group of nearly 100,000 galaxies in nine infrared wavelengths. From this dataset, the astronomers isolated 250 of the faintest and reddest galaxies and targeted them with another of JWST’s instruments: the Near Infrared Spectrometer (NIRSpec).
NIRSpec was designed to collect the light emitted by celestial bodies and decompose it into its component colors. This process creates rainbow-like graphs called spectra. Astronomers can analyze a galaxy’s spectrum to find out everything from its elemental composition to how many stars are inside it and even its distance from Earth.
The latter is done by measuring a phenomenon known as redshift. Light from distant galaxies can take billions of years to reach our planet. During that time, the wavelengths of this light get longer and longer, slowly moving into the “red” part of the light spectrum.
As light travels toward Earth from its source, it will inevitably pass through vast clouds of interstellar gas and dust. These clouds are known to absorb certain wavelengths of light well, while allowing others to pass through them relatively unhindered. This interference creates a distinct pattern in the rainbow spectrum.
A graph showing the positions and redshifts of galaxies Anton M. Koekemoer (STScI), Christopher Willmer (University of Arizona), JWST PEARLS Team Image processing: Rolf A. Jansen (ASU), Alyssa Pagan (STScI))
The scientists were able to calculate the age and distance of distant galaxies by observing how much the patterns in the spectra changed from their predicted positions due to redshift.
Using this technique, scientists have discovered four extremely ancient galaxies found within the JWST data, believed to have formed just 300 million years after the creation of the universe in the Big Bang. This makes it 100 million years younger than the oldest galaxy ever discovered by the Hubble Space Telescope.
This means that the light detected by the JWST left its source about 13.4 billion years ago, at a time when the universe was only 2% of its current age. The record ages of the galaxies will make them invaluable to scientists seeking to uncover the evolutionary secrets of the early universe.
‘It is difficult to understand galaxies without understanding the earliest periods of their evolution,’ explained astronomer Sandro Takela of the University of Cambridge, co-author of a study describing the findings. University of Arizona). “As with humans, much of what happens next depends on the influence of these first generations of stars.”
“So many intergalactic questions await Webb’s transformational opportunity, and we’re thrilled to be able to play a part in uncovering this story.”
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Image credit: Northrop Grumman.
Anthony is a freelance contributor covering science and video game news for IGN. He has over eight years of experience covering groundbreaking developments in various scientific fields and there is no time to fool him. Follow him on Twitter @BeardConGamer
