NASA's James Webb Telescope (JWST) has made a surprising discovery at the edge of our universe, which astronomers said should not exist.
The telescope captured imagery of three 12.8-billion-year-old 'Red Monster' galaxies, one billion years older than the Big Bang, roughly the size of the Milky Way.
Astronomers suggested that the formation of stars - and thus galactic growth - in the early universe was far more efficient than previously thought, prompting experts to rethink existing galaxy formation models.
Under the most widely accepted cosmological model - Lambda Cold Dark Matter (LCDM) model - these 'Red Monster' galaxies shouldn't exist, researchers noted.
LCDM posits that the first galaxies that formed in the universe did not have enough time to become as massive as these newly discovered galaxies appear to be.
'Finding three such massive beasts among the sample poses a tantalizing puzzle', said Stjn Wuyts, study co-author and Hiroko Sherwin Chair in Extragalactic Astronomy at the University of Bath, in a statement.
'Many processes in galaxy evolution have a tendency to introduce a rate-limiting step in how efficiently gas can convert into stars, yet somehow these Red Monsters appear to have swiftly evaded most of these hurdles,' he added.
This isn't the first time that JWST has spotted 'impossibly large' ancient galaxies, as these three are just the latest in a series of discoveries that have forced astronomers to question their understanding of how early galaxies formed.
The researchers call these newly discovered galaxies 'Red Monsters' due to their gigantic size and high dust content, which gives them a distinct red appearance in telescope images
The researchers are calling the three most recently discovered ones 'Red Monsters' due to their gigantic size and high dust content, which gives them a distinct red appearance in telescope images
Wuyts and his colleagues conducted their study as part of the JWST First Reionization Epoch Spectroscopically Complete Observations (FRESCO) survey.
This program set out to systematically analyze a complete sample of emission-line galaxies (ELGs) within the first billion years of the Big Bang, according to the statement.
ELGs are galaxies that exhibit strong emission lines in the spectra of light they emit.
'These emission lines appear as bright lines at specific wavelengths, standing out against the darker background of the spectrum,' the statement reads.
The researchers analyzed these emission lines to gather data on the distances of the galaxies in the sample and emission line strengths. This knowledge then allowed them to measure the amount of stars contained within each galaxy.
Most of the galaxies they surveyed fit existing models. But three were found to be surprisingly massive - the Red Monsters.
JWST was able to reveal the existence of these galaxies for the first time thanks to the unique capabilities of its Near Infrared Camera
The researchers published their findings in the journal Nature on November 13.
Astronomers widely believe that galaxies form within huge halos of dark matter whose gravity captures gas and forces it into gravitationally-bound structures.
Typically, only 20 percent of that gas - at most - becomes stars and galaxies. Therefore, it takes a long time for galaxies to reach massive sizes.
But the Red Monsters challenge this view. In order for these galaxies to have achieved their size, they must be forming stars nearly two times faster than galaxies that were formed later on in cosmological history, the researchers concluded.
'Our findings are reshaping our understanding of galaxy formation in the early universe,' Mengyuan Xiao, study lead author and postdoctoral researcher at the University of Geneva in Switzerland, said in the statement.
A JWST survey published in February 2023 found six galaxies that formed just 500 to 700 million years after the Big Bang, and are 100 times more massive than they should be
This research adds to a growing body of galaxy observations that contradict this understanding, demonstrating that we still have much to learn about the early universe.
For example, a JWST survey published in February 2023 found six galaxies that formed just 500 to 700 million years after the Big Bang, and are 100 times more massive than astronomers would expect them to be.
While many experts believe that these discoveries call for a re-examination of current cosmological models, others have suggested that the nonsensical observations may optical illusions.
A study published in August argued that the presence of black holes in some of these early galaxies could have made them appear much brighter and larger than they actually were.
Getting to the bottom of this cosmological mystery will require further investigation into these anomalous galaxies through the unique capabilities of JWST.
'Already in its first few years of operation, JWST has thrown us a couple of curveballs,' Wuyts said.