The small red dot marked inside the white box on this James Webb Space Telescope image is an early galaxy, seen as it appeared just 350 million years after the Big Bang.
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The small red dot marked inside the white box on this James Webb Space Telescope image is an early galaxy, seen as it appeared just 350 million years after the Big Bang.
STScI/NASA
New images of the universe, taken by the James Webb Space Telescope, show that galaxies started forming faster and earlier than expected.
The telescope was launched again in December and it now orbits the sun about a million miles from Earth. Its giant mirror allows it to detect faint light that has traveled for nearly the entire history of the 13.8 billion-year-old universe. That means it can effectively see what galaxies looked like in the past.
The snapshots taken so far have both thrilled and confused scientists, because it turns out that many luminous galaxies existed when the universe was very young.
“Just a few hundred million years after the Big Bang, there were so many galaxies,” says Tommaso Treu, an astronomer at the University of California at Los Angeles. “JWST has opened a new frontier, bringing us closer to understanding how it all began.”
In research papers published year Astrophysics MagazineTreu and other astronomers report the discovery of one galaxy dating back to just 450 million years after its inception and another 350 million years old.
The discovery then broke the record set by the Hubble Space Telescope in 2016, when it glimpsed a galaxy called GN-z11, which existed about 400 million years after the Big Bang.
Astronomers Garth Illingworth of the University of California, Santa Cruz was part of the team that found the GN-z11 and said seeing it was “a huge surprise”. But now, with the help of their new space telescope, scientists know it’s not just a strange exception – because they have at least two more examples.
The Red Dot is a new galaxy discovered 350 million years ago after the Big Bang.
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“The galaxies we’re talking about are very bright, and so they lurk below the limits of what Hubble can do,” said Jane Rigby, an operations project scientist for the James Webb Space Telescope. “They’re right there waiting for us.”
Since astronomers began using JWST, some have claimed to have discovered galaxies from even earlier times, such as 250 million years after the Big Bang. But those are more expected observations.
“We felt very confident about these two things, but less confident about the others,” says Illingworth. “There’s certainly a lot of discussion going on.”
The two newly seen galaxies are both much smaller than our home galaxy, the Milky Way, and one appears to be surprisingly elongated.
Because JWST has seen so many bright, early galaxies, astronomers are having to rethink their old ideas about the evolution of the universe.
“What’s interesting to us, from a theoretical point of view, is that there may be some open questions about how these galaxies were able to form their stars so much earlier that we have can detect a large number of them,” said Jeyhan Kartaltepe of the Rochester Institute of Technology.
Search for galaxies like these and build a deeper understanding of how the universe evolved to get to where it is today, which is why astronomers have spent decades and $10 billion la to design and launch JWST.
“We can see that we are really on track to realize our dream of understanding galaxies as soon as possible,” said Illingworth. “The past few months have been exciting, but there’s still a lot to learn ahead.”
