Enlarge image
The red points of light represent six possible galaxies that are more than 13 billion years old
Photo: NASA/ESA/CSA/I Labbe (Swinburne University of Technology)/ REUTERS
When Erica Nelson spotted the red dots, she was taken aback.
The astrophysicist from the University of Colorado Boulder, together with other researchers, viewed the first images from the James Webb space telescope, which NASA published last July.
Red light is a signal for very old stars.
Because as light moves through the universe, it is effectively stretched and shifted into the red light spectrum.
What Nelson and her team saw was not only red, but also unusually large and bright. What could it be?
The researchers initially believed it was a mistake, but now they are convinced that they have found the traces of six ancient, huge galaxies, they report in the journal "Nature".
The discovery would contradict current theories in astronomy.
"We expected to find only small, young baby galaxies from this period," says astronomer Joel Leja, who helped make the discovery, according to the Guardian.
"But we have found galaxies, some of which are as large as our own Milky Way."
Doubts about the Dark Ages
The putative galaxies are about 13.5 billion years old and thus formed about 500 to 700 million years after the Big Bang - a short period of time in cosmology.
When the galaxies formed, the universe was only 3 percent of its current age.
Actually, galaxies shouldn't have had so much time to grow so big so shortly after the Big Bang.
At least that's what common theories say.
According to this, after an initial expansion, the universe has practically taken a lull of a few hundred million years.
During this time, also known as the dark ages, the gases in the universe cooled down until they formed the first stars and galaxies.
According to current models, there wasn't enough mass at the time to form galaxies as large as the new discovery suggests.
A possible explanation would be that the density of matter in the early Universe must have been about two to five times greater than previously thought.
Or the galaxies could have formed in a previously unknown way.
“The discovery of such massive galaxies so shortly after the Big Bang suggests that the dark ages may not have been dark after all.
And that the universe started forming stars much earlier than thought,” says Emma Chapman, an astrophysicist at the University of Nottingham, who was not involved in the study.
"They're fundamentally different, really bizarre creatures," says astrophysicist Ivo Labbe of Australia's Swinburne University of Technology about the discovery.
Assuming the Milky Way was a 1.75 meter tall, 70 kilogram adult, the galaxies now discovered would be one-year-old babies, just as heavy but only three inches tall.
"The early universe is a freak show," says Labbe.
However, before the laws of astronomy can be rewritten, further investigations must show whether the galaxies that have now been discovered are actually as old and as large as the images suggest.
The discoveries are still considered possible galaxies.
Further analysis should now rule out other possible explanations.
In theory, they could also be supermassive black holes.
The research team hopes to target the area with the James Webb's high-resolution near-infrared spectrometer.
The light spectrum could clarify which elements the objects contain and whether they are actually galaxies.
"A spectrum will immediately tell us whether these objects are real," says Leja.
The James Webb telescope, built by the USA, Canada and the European space agency ESA, was launched from French Guiana at the end of 2021 and has been peering into the depths of space 1.6 million kilometers from Earth since last summer.
Scientists hope to use the device, which costs ten billion dollars, to look back to the formation of the first stars and galaxies and gain new insights into the formation of the universe.
koe/Reuters