Space: the first galaxies may have formed earlier than expected

The first galaxies may have formed earlier than astronomers thought, according to the first observations from the new James Webb Space Telescope, which in just a few months has already shaken scientific understanding of the cosmos.

“One way or another, the Universe has managed to form galaxies faster and sooner than we thought,” said Tommaso Treu, a professor of astronomy at UCLA University.

One of the main missions of the James Webb telescope, which is in its fifth month of observations, is to study the first galaxies formed after the Big Bang, which occurred 13.8 billion years ago.

“It’s a surprise”

Based on elaborate cosmological models, scientists thought it would “take time” to find them, said astrophysicist Jeyhan Kartaltepe.

However, in just a few months, James Webb has already identified many new young galaxies, including one that existed only 350 million years after the Big Bang, 50 million years less than the previous observed record.

“It’s a surprise that there are so many that were formed so soon,” said Jeyhan Kartaltepe.

“No one would have believed that the dark ages would end so soon”

In addition to their number, one thing amazed scientists: their high luminosity. “We immediately concluded that they are massive, and this raises a real puzzle: how could they have formed so many stars in such a short time?” summarized Garth Illingworth of the University of California at Santa Cruz.

To be able to do that, “these galaxies would have to have started forming maybe only 100 million years after the Big Bang,” he explained. “No one would have believed that the dark ages would end so soon.”

An alternative hypothesis would be that these galaxies actually host so-called population III stars, very different from those we know. These extraordinarily bright early stars have so far only been theorized, not observed.

The incredible capabilities of the James Webb Telescope have also revealed the appearance of some of these galaxies.

Thanks to this new observatory, “we are really on the right track to make this dream of understanding galaxies of the earliest ages come true,” Garth Illingworth marveled.