Key Takeaways:
- The JWST discovered over a thousand disk galaxies resembling our Milky Way in the early universe, more than 10 billion years ago.
- These disk galaxies were unexpected because violent mergers were thought to be common then, preventing such delicate structures from forming.
- The discovery suggests disk galaxies are ten times more abundant in the early universe than previously believed.
- JWST hints at galaxy structures forming much earlier than anticipated, challenging current theories.
- The prevalence of disk galaxies early on suggests life might have begun in the universe much sooner than we thought.
More than a thousand galaxies that strangely resemble our own Milky Way have been discovered by the James Webb Space Telescope (JWST) to be hiding out in the early universe.
The Milky Way twins were discovered by JWST more than 10 billion years into the universe’s past, when violent galactic mergers were assumed to have made the existence of an abundance of such delicate galaxies impossible. They have the shape of warped vinyl records and delicate spiral arms.
However, new research indicates that the disk galaxies are ten times more common in the early universe than previously believed by astronomers. The odd finding joins other JWST discoveries that suggest the origins of large galaxies and life itself is a mystery that is becoming more and more mysterious. The researchers published their findings in The Astrophysical Journal.
The lead study author, Leonardo Ferreira, is an astronomer at the University of Victoria in Canada. “For over 30 years it was thought that these disk galaxies were rare in the early universe due to the common violent encounters that galaxies undergo,” Ferreira said. “The fact that JWST finds so many is another sign of the power of this instrument and that the structures of galaxies form earlier in the universe, much earlier in fact, than anyone had anticipated.”
The earliest star clusters were assumed to have transformed into dwarf galaxies by the time most theories of galaxy formation start, which is one to two billion years into the universe’s history. These dwarf galaxies subsequently began cannibalizing each other, sparking a free-for-all of violent galactic mergers that (after 10 billion years) resulted in large galaxies like our own.
A disk galaxy is the Milky Way. It is one of the most prevalent kinds of galaxies in the universe today, with its spiral arms and squashed sombrero shape. But back in the early days of the universe, when space was more dense and dwarf galaxies multiplied, astronomers had long believed that galaxies like our own would soon spiral out of shape.
However, using the JWST to look back 9 billion to 13 billion years, the scientists found that 1,672 of the 3,956 galaxies they had observed were disk galaxies similar to our own. A large number of these galaxies date back to the early billions of years of the universe’s existence.
According to a statement from Christopher Conselice, a professor of extragalactic astronomy at the University of Manchester and co-author of the study, “using the Hubble Space Telescope we thought that disk galaxies were almost non-existent until the universe was about 6 billion years old.” “These new JWST results push the time these Milky Way–like galaxies form to almost the beginning of the universe.”
“This implies that most stars exist and form within these galaxies which is changing our complete understanding of how galaxy formation occurs,” he said. “Based on our results astronomers must rethink our understanding of the formation of the first galaxies and how galaxy evolution occurred over the past 10 billion years.”
Astronomers typically believe that since we live in a disk galaxy, there must be favorable conditions there for the emergence of life. If so, it’s feasible that life began in the universe sooner than previously believed.
