The young universe unexpectedly contained many galaxies shortly after the big bang

In this image from the James Webb Space Telescope, Huojing Yan and colleagues discover 87 extremely distant galaxies.  Image NASa, ESA, CSA, and STScI

In this image from the James Webb Space Telescope, Huojing Yan and colleagues discover 87 extremely distant galaxies.Image NASa, ESA, CSA, and STScI

Since the universe is 13.8 billion years old, this means that galaxies formed less than 150 million years after the Big Bang. “Maybe we should rethink our ideas about the birth of galaxies in the early universe,” said Huaqing Yan of the University of Missouri.

Yan presented his results on Monday at the Winter Conference of the American Astronomical Society in Seattle, USA. It’s the first major astronomical conference since the Webb telescope officially went live in July, more than half a year after its launch on Christmas Day 2021. According to Gene Rigby of NASA’s Goddard Space Flight Center, who delivered the opening lecture, the Hubble Space Telescope is better behind than Expected. “It is now the most powerful telescope ever built,” says Rigby.

37 billion light years away

Yan and his colleagues studied 87 very distant galaxies in images from the Webb telescope taken last summer. If their approximate distances are confirmed by future measurements, the outermost samples will now be about 37 billion light-years away, due to the expansion of the universe. Never before had objects been observed at such great distances. In addition, the number of distant galaxies is much greater than expected.

Jeyhan Kartaltepe of the Rochester Institute of Technology came to similar conclusions, also based on images from the James Webb Telescope. “We see that disk-shaped galaxies like our own Milky Way already existed shortly after the Big Bang,” she says. “That in itself isn’t very surprising, but having so many of them is pretty cool.” Everything seems to indicate that the first galaxies formed much earlier and in far greater numbers than current theories predict.

Independent confirmation

NASA astronomer James Rhodes doesn’t think all ideas about the early evolution of the universe are ready for garbage disposal right now. “Future resolution measurements should show whether Yan and colleagues’ determinations of distances are really correct for all of the candidate galaxies,” he says. “I expect there are a few specimens that, on closer examination, are closer than currently assumed.”

An engineer inspects the mirror parts of the James Webb Space Telescope.  Image by David Higginbotham/NASA/MSFC

An engineer inspects the mirror parts of the James Webb Space Telescope.Image by David Higginbotham/NASA/MSFC

This independent confirmation may take some time, says Yan: For this, additional observation time on the James Webb Telescope would have to be requested. But he says that even if a large portion of the 87 objects are less distant than previously thought, the number of extremely distant galaxies remains staggeringly high.

The most distant galaxy seen by the James Webb Space Telescope, after which it is known with absolute certainty, is so far away that we see it as it appeared 320 million years after the Big Bang. In doing so, the Hubble Space Telescope record was shattered anyway: Hubble couldn’t see more than 400 million years after the Big Bang.

“More than 160 scientific publications have already been published based on Webb’s observations,” says Jane Rigby. “I can’t wait to see what we find out next.”

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