Washington DC - Four galaxies that existed more than 13 billion years ago have been identified and confirmed by scientists as the earliest known to date.

These galaxies were present around 350 million years after the Big Bang, when the universe was just 2% of its current age.

The confirmation comes from the data taken from NASA’s James Webb Space Telescope (JWST), which is the largest and the most powerful telescope ever built.

Previously, images taken by JWST flagged these galaxies as potential candidates from the early universe, but experts used a technique known as spectroscopy, which measures light to determine the speed and composition of objects in space, to calculate the age of these galaxies, named JADES-GS-z10-0, JADES-GS-z11-0, JADES-GS-z12- and JADES-GS-z13-0.

The experts said their findings corroborate their status as the earliest galaxies ever observed.

Dr Emma Curtis-Lake, Webb Fellow at the University of Hertfordshire and lead author on one of the two scientific papers published as preprints, said: "It was crucial to prove that these galaxies do indeed inhabit the early universe, as it’s very possible for closer galaxies to masquerade as very distant galaxies.

"Seeing the spectrum revealed as we hoped, confirming these galaxies as being at the true edge of our view, some further away than Hubble could see – it is a tremendously exciting achievement for the mission."

She added: "This confirms we are in new frontier of our investigations into the birth of galaxies."

More than 80 astronomers from 10 countries were involved in the research as part of the JWST Advanced Deep Extragalactic Survey (JADES) program.

The data comes from two onboard JWST instruments – the Near-Infrared Spectrograph (NIRSpec) and the Near-Infrared Camera (NIRCam) – which were developed to hunt for the oldest and faintest galaxies in the universe.

Prof Andrew Bunker, professor of astrophysics at the University of Oxford, said: "Our observations suggest that the formation of the first stars and galaxies started very early in the history of the universe."

For the studies, the team focused on a small patch of sky for 10 days. The JADES astronomers were able to observe this patch of sky in nine different infrared wavelength ranges.

The image reveals nearly 100,000 galaxies, each billions of light years away, in a pinprick of the sky equivalent to looking at a mobile phone screen across a football field, according to the researchers.

The astronomers were able to identify the very earliest galaxies by analyzing their "distinctive banded" colors, which are visible in infrared light but invisible in other wavelengths.

Brant Robertson, from the University of California Santa Cruz, who is one of the study co-authors, said: "For the first time, we have discovered galaxies only 350 million years after the Big Bang, and we can be absolutely confident of their fantastic distances.

"To find these early galaxies in such stunningly beautiful images is a special experience."