By Daily Mail (U.S.) | Created at 2025-04-02 20:41:43 | Updated at 2025-04-03 16:43:19
20 hours ago
NASA's James Webb Space Telescope (JWST) has captured the earliest evidence of light shining through the cosmos.
An international team of researchers used JWST to observe an ancient galaxy that emitted light just 330 million years after the Big Bang, when a thick fog of neutral hydrogen gas made it difficult for light to cut through the darkness.
This galaxy, called JADES-GS-z13-1-LA, somehow managed to shine even though its light should have been completely absorbed by the dense fog.
JADES is one of the most distant galaxies in the known universe. Its light had to travel nearly 13.5 billion light-years to reach JWST, which also means that this galaxy is almost as ancient as the universe itself.
The farther out in space astronomers look using telescopes like JWST, the further back in time they're seeing, almost all the way to the Big Bang.
What's more, JWST detected a Lyman-alpha emission from JADES, which is a specific, distinctly bright wavelength of light that is very easily absorbed by neutral hydrogen.
The fact that the telescope spotted this emission means that the fog immediately surrounding the galaxy must dissipated, according to the researchers.
This suggests JADES was actively clearing the neutral hydrogen gas away.
The red dot at the center of this image is the ancient galaxy JADES GS-z13-1, captured by NASA's James Webb Space Telescope (JWST)
'This result was totally unexpected by theories of early galaxy formation and has caught astronomers by surprise,' Roberto Maiolino, co-researcher and astrophysicist at the University of Cambridge and University College London, said in a statement.
The universe began roughly 13.8 billion years ago with the Big Bang. In its early years, it looked completely different than the shining, sparkling cosmos we see today.
Beginning 400,000 years after the Big Bang and lasting hundreds of millions of years, the universe was in a period known as the 'dark ages' when no planets, stars, or galaxies existed.
During this time, only a fog of hydrogen atoms floated around in the darkness.
But around 680 million years after the Big Bang, the first stars and galaxies began to form.
They emitted ultraviolet radiation out into the darkness, which started breaking apart the hydrogen atoms and gradually made the universe transparent to light.
Over another several million years, more and more stars formed and clumped together into galaxies.
By 1.1 billion years after the Big Bang, the cosmos was no longer an opaque sea of blackness, but a transparent, illuminated universe.
This image shows the JADES galaxy's spectrum graphic, or a graph of the different wavelengths of light or other form of electromagnetic radiation emitted by a celestial object
The James Webb Space Telescope is the most powerful ever built. It allows astronomers to peer across time and space to see the earliest formations in our universe
But after analyzing the JADES galaxy using JWST's imaging and spectroscopy instruments, the researchers found that it dates back to the middle of the cosmic dark ages.
At that time, the neutral hydrogen gas should have been so thick that it smothered any light emitted by early stars or galaxies.
'We really shouldn't have found a galaxy like this, given our understanding of the way the universe has evolved,' Kevin Hainline, co-author and astronomer at the University of Arizona, said in the statement.
'We could think of the early universe as shrouded with a thick fog that would make it exceedingly difficult to find even powerful lighthouses peeking through, yet here we see the beam of light from this galaxy piercing the veil,' he said.
'This fascinating emission line has huge ramifications for how and when the universe reionized.'
The team published their findings in the journal Nature.
At this time, the researchers aren't sure how or why this galaxy emitted Lymen-alpha radiation. But they do have some theories.
One possible explanation is that JADES hosts extremely massive, hot stars that are far more efficient at producing ionizing radiation that the average star today.
In that case, these stars may have heated the surrounding gas to temperatures more than 15 times hotter than the surface of the sun, resulting in an extremely powerful radiation emission.
An alternative theory is that the JADES galaxy contains an active supermassive black hole, and the radiation emitted by material falling into that black hole ionized nearby gas.
The researchers did find some evidence to support this idea. Their measurement of JADES' size suggests it's extremely compact, which is characteristic of galaxies with black holes.
Regardless of how the light from this ancient galaxy managed to cut through the darkness of the early universe, capturing it offers a look at what may be the first light from the oldest generation of stars in the cosmos, the researchers say.
