24/7 Space News
TIME AND SPACE
James Webb captures earliest hint of cosmic clarity
illustration only
James Webb captures earliest hint of cosmic clarity
by Robert Schreiber
Berlin, Germany (SPX) Apr 01, 2025

From a fiery origin to its slow expansion and eventual formation of structure, the Universe's evolution has long fascinated scientists. A key chapter in this story unfolded a few hundred million years after the Big Bang, when the earliest galaxies and stars began coalescing from vast reservoirs of primordial gas. Astronomers have detected galaxies dating back to less than 300 million years post-Big Bang, but the precise timing and mechanisms of their emergence remain hotly debated.

One early galaxy has now illuminated a critical shift in the young cosmos: the first signs of the Universe becoming transparent.

A foggy challenge

The birth of the first galaxies was veiled by dense clouds of neutral hydrogen gas. These early galaxies emitted powerful ultraviolet (UV) radiation, but neutral hydrogen absorbs UV light efficiently. As a result, much of the light from these young objects was obscured, particularly in the UV spectrum, making them nearly impossible to detect directly at those wavelengths.

The light that does escape comes in less energetic forms, presenting a serious obstacle to astronomers trying to observe this formative period in cosmic history.

Clearing the cosmic haze

Over time, UV photons from the earliest stars and galaxies began to ionize the surrounding hydrogen atoms, splitting them and rendering the gas transparent to radiation. This transition, known as the Epoch of Reionization, represents a major milestone in the Universe's evolution.

Researchers continue to investigate when and how this process began and what sources triggered it. The prevailing theory held that reionization commenced around 500 million years after the Big Bang and concluded another half-billion years later.

A new finding by astronomers at the Cosmic Dawn Center (DAWN), part of the Niels Bohr Institute and DTU Space, now suggests this process may have started significantly earlier. Their study focused on one of the most ancient galaxies yet discovered and offers compelling evidence of an ionized region surrounding it.

"Young galaxies shine brightest at a very specific wavelength of light, originating from hydrogen. To astronomers, this light goes under the name 'Lyman alpha'. Because of its short UV wavelength, it is easily absorbed by the surrounding medium, and therefore no galaxy from when the Universe was less than half a billion years old has showed us this particular kind of light."

Bubble of light

This status quo has now been upended by the detection of Lyman alpha emissions from galaxy JADES-GS-z13-1, one of the most distant known.

How could such light pass through a Universe still saturated with opaque hydrogen?

"We know from our theories and computer simulations, as well as from observations at later epochs, that the most energetic UV light from the galaxies "fries" the surrounding neutral gas, creating bubbles of ionized, transparent gas around them," Witstok elaborates. "These bubbles percolate the Universe, and after around a billion years, they eventually overlap, completing the epoch of reionization. We believe that we have discovered one of the first such bubbles."

This isolated Lyman alpha signal indicates that a transparent, ionized zone surrounds the galaxy, permitting the light to escape and reach our instruments.

A view only Webb could provide

The unprecedented sensitivity and spectral capabilities of the James Webb Space Telescope enabled this landmark detection.

"We knew that we would find some of the most distant galaxies when we built Webb," says Peter Jakobsen, affiliated professor at DAWN, project scientist behind James Webb's spectrograph NIRSpec, and second-author of the study. "But we could only dream of one day being able to probe them in such detail that we can now see directly how they affect the whole Universe."

Although extremely bright stars are one potential source of such ionizing radiation, another hypothesis remains open:

"Most galaxies are known to host a central, supermassive black hole. As these monsters engulf surrounding gas, the gas is heated to millions of degrees, making it shine brightly in X-rays and UV before disappearing forever. This is another viable cause of the bubbles, which we will now investigate," Witstok concludes.

Research Report:Witnessing the onset of reionization through Lyman-a emission at redshift 13

Related Links
University of Copenhagen - Faculty of Science
Understanding Time and Space

Subscribe Free To Our Daily Newsletters
Tweet

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
TIME AND SPACE
Howard University researcher explores quantum bounds on life's computational power
Los Angeles CA (SPX) Mar 30, 2025
Over 80 years ago, Erwin Schrodinger asked a profound question about the nature of life in his 1944 lectures at Trinity College Dublin, later published as "What is Life?" Now, in the 2025 International Year of Quantum Science and Technology, Philip Kurian of Howard University has revisited that question, applying modern quantum mechanics to redefine the limits of biological computation. Kurian, founding director of the Quantum Biology Laboratory (QBL), has published a new study in *Science Advance ... read more

TIME AND SPACE
Safely back on Earth, once-stranded US astronauts ready to fly again

Delft and Brown researchers unveil ultrathin sails for laser propulsion in space

SpaceX's Crew 11 to space station named: 2 from NASA, plus Russia, Japan

SpaceX to launch private astronauts on first crewed polar orbit

TIME AND SPACE
ULA Vulcan earns green light for national security launches

The Sky's Not the Limit for NASA's Next-Gen Landing Navigation Tech

European orbital rocket crashes after launch

Rocket Lab tapped to join US Space Force national security launch initiative

TIME AND SPACE
Martian dust may endanger astronaut health during surface missions

ExoMars rover to land on Mars aboard European-built platform

Visiting Mars on the Way to the Outer Solar System

Sols 4488-4490: Progress Through the Ankle-Breaking Terrain

TIME AND SPACE
Space station advances muscle and semiconductor science

China logs 15th orbital mission with launch of Tianlian II-04

China's Galactic Energy expands Yunyao satellite network with successful launch

Shenzhou XIX astronauts complete third spacewalk outside Tiangong

TIME AND SPACE
SpaceX launches another 28 satellites into orbit from Florida

Sateliot secures major backing to scale 5G IoT satellite network

SKY Perfect JSAT contracts Thales Alenia Space for JSAT 32 satellite project

Globalstar launches advanced control center in Louisiana to boost satellite operations

TIME AND SPACE
Radiation belt wisp mapped inside anomaly by Macao satellite

NASA cloud tech empowers private mission planners

Redwire expands space-based pharmaceutical research under new NASA contract

Sidus Space Expands Presence in Asia With Orlaith AI and FeatherEdge Technology

TIME AND SPACE
How calcium may have guided early molecular directionality

Incredible Journey of Pristine Meteorite Reveals Survival Secrets

Fluorescent caves could explain how life persists in extraterrestrial environments

Atmospheres of new planets might have unexpected mixtures of hydrogen and water

TIME AND SPACE
20 years of Hubble data reveals evolving weather patterns on Uranus

NASA's Hubble Telescope May Have Uncovered a Triple System in the Kuiper Belt

NASA's Europa Clipper Leverages Mars for Critical Gravity Assist

Oort cloud resembles a galaxy, new study finds

Subscribe Free To Our Daily Newsletters




The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.