Six ancient 'universe breaker' galaxies discovered
The galaxies date back to within 600 million years of the Big Bang.
Six massive ancient galaxies, which astronomers are calling "universe breakers" appear to have been discovered, which may upend existing theories of cosmology.
The galaxies, detected by the £8.3bn James Webb telescope, are believed to date back to within around 600 million years of the Big Bang.
While the year-old telescope has spotted older galaxies dating to within 300 million years of the beginning of the universe, the size and maturity of the mega-galaxies have stunned scientists.
Astronomers thought they had made a mistake when they spotted the "monsters".
Lead researcher Ivo Labbe, from Australia's Swinburne University of Technology, said: "While most galaxies in this era are still small and only gradually growing larger over time, there are a few monsters that fast-track to maturity. Why this is the case or how this would work is unknown."
"We were mind-blown, kind of incredulous," Mr Labbe said.
The six galaxies appear to weigh billions of times more than our sun, according to the scientists who published their results in the journal Nature.
But they are believed to be extremely compact, squeezing in as many stars as the Milky Way but in a relatively tiny slice of space.
Pennsylvania State University's Joel Leja, who took part in the study, said the discovery "upends what many of us had thought was settled science".
"It turns out we found something so unexpected it actually creates problems for science. It calls the whole picture of early galaxy formation into question."
Existing theories suggest that after a period of rapid expansion, the universe spent several hundred million years cooling down enough for gas to coalesce and collapse into the first stars and galaxies began to form. This period is known as the dark ages.
The observations of the new galaxies were among the data set that came from the Webb telescope.
NASA and the European Space Agency's Webb is considered the successor to the Hubble Space Telescope which was launched almost 33 years ago.
Unlike the Hubble, the bigger and more powerful Webb can see through clouds of dust with its infrared vision and find previously undiscovered galaxies.
Scientists hope to eventually observe the first galaxies and stars formed after the creation of the universe 13.8 billion years ago.
The research team is still waiting for official confirmation of the galaxies through sensitive spectroscopy. Mr Leja said it's possible that a few objects might not be galaxies, but obscured supermassive black holes.
While some may prove to be smaller, "odds are good at least some of them will turn out to be" galactic giants, Mr Labbe said. "The next year will tell us."
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