The James Webb Space Telescope has peered back in time to detect two of the earliest and the most distant known galaxies ever seen, allowing astronomers to observe the universe as it was when it was only 300 million years old.
The record-breaking galaxies, dubbed GS-z14-0 and GS-z14-1, were identified by an international team of scientists who were part of the Jades (JWST Advanced Deep Extragalactic Survey) collaboration.
GS-z14-0 appears as it was roughly 290 million years after the Big Bang, an era which scientists call the cosmic dawn.
And GS-z14-1 is seen as it was around 300 million years after the cosmos came into existence.
The universe is thought to be around 14 billion years old, so it means the galaxies observed are only 2% of its current age.
Until now, the telescope’s record holder was a galaxy known as GS-z13-0, which was seen at 325 million years after the Big Bang.
The JADES team has found the new farthest galaxy humans have ever seen: JADES-GS-z14-0. This source, which is found at a redshift of 14.32, is so distant we’re seeing it as the Universe was when it was only **290 million years old.** pic.twitter.com/LUOVqXu9Oy
— Kevin Hainline (@Kevin_Hainline) May 30, 2024
Astronomers used a cosmological phenomenon known as redshift to explain how distant a galaxy is from Earth.
As the universe expands, the space between galaxies stretches, which also causes the light travelling through this space to stretch.
The telescope uses this stretching effect, or redshift, to detect galaxies from very early in the universe.
Dr Francesco D’Eugenio of the Kavli Institute for Cosmology at the University of Cambridge, said: “These galaxies join a small but growing population of galaxies from the first half billion years of cosmic history where we can really probe the stellar populations and the distinctive patterns of chemical elements within them.”
The galaxies were spotted in a region of space known as the Hubble Ultra Deep Field in the constellation Fornax, which houses around 10,000 galaxies.
Astronomers also said they were surprised by how “stupendously bright” GS-z14-0 was.
Dr Stefano Carniani of the Scuola Normale Superiore in Pisa, Italy, added: “It is stunning that the universe can make such a galaxy in only 300 million years.”
GS-z14-0 measures over 1,600 light-years in diameter, the researchers said.
They believe the notable size and brightness of this galaxy suggests is likely being fuelled by young stars.
When studying the wavelengths of light emitted by GS-z14-0, astronomers found signs of hydrogen and potentially oxygen atoms in the surrounding gas, which are common in young galaxies.
Jakob Helton, graduate student at the University of Arizona, said: “We are seeing extra emission from hydrogen and possibly even oxygen atoms, as is common in star-forming galaxies, but here shifted out to an unprecedented wavelength.”
JWST was launched in 2021 as part of a joint £7.8bn (10bn dollar) mission between Nasa, European Space Agency and Canadian space agency.
Its key aim is to help shed light on how the universe originated and evolved.
