New baby pictures of the universe taken by the James Webb Space Telescope show that galaxies are starting to form faster and earlier than expected.
The telescope was launched back in December and is now orbiting the Sun about a million miles from Earth. Its giant mirror allows it to detect faint light that has traveled through nearly the entire history of the 13.8 billion-year-old universe. This means that it can effectively see what galaxies looked like in the past.
The images so far have both excited and puzzled scientists, as they reveal that many bright galaxies existed when the universe was very young.
“Just a few hundred million years after the Big Bang, there are already many galaxies,” he says Tommaso Treu, an astronomer at the University of California, Los Angeles. “JWST has opened a new frontier that brings us closer to understanding how it all began.”
In research documents was published in Astrophysical Journal LettersTreu and other astronomers report that one galaxy is only 450 million years after its inception and the other 350 million years earlier.
This latest discovery broke the record set by the Hubble Space Telescope in 2016, when it caught a glimpse of a galaxy called GN-z11 that existed about 400 million years after the Big Bang.
an astronomer Garth Illingworth The University of California Santa Cruz was part of the team that found GN-z11 and said it was a “big surprise” to see it. But now, with the help of their new space telescope, scientists know it’s not just a strange outlier — because they have at least two more examples.
“These galaxies we’re talking about are bright, and so they were hidden below the limits of what Hubble could do,” he says. Jane Rigby, operations project scientist for the James Webb Space Telescope. “They were waiting for us there.”
Since astronomers began using JWST, some have claimed to have dated galaxies to an earlier era, 250 million years after the Big Bang. But these are more preliminary observations.
“We have a lot of confidence in those two, but less confidence in the others,” says Illingworth. “There’s definitely a lot of discussion going on.”
The two newly discovered galaxies are both very small compared to our home galaxy, the Milky Way, and one appears unexpectedly elongated.
As very early, bright galaxies have been seen by JWST, astronomers are having to rethink their old ideas about the evolution of the universe.
“It’s theoretically interesting to us that maybe there are some open questions about how these galaxies formed their stars so early that we were able to detect large numbers of them.” Ceyhan Kartaltepe from the Rochester Institute of Technology.
Finding galaxies like these and better understanding how the universe evolved into what it is today is why astronomers spent decades and $10 billion designing and launching JWST.
“We can see that we are really moving towards realizing the dream of understanding galaxies at the earliest possible time,” says Illingworth. “The last few months have been exciting, but we have a huge amount to learn.”
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