An international group of astrophysicists has discovered several mysterious objects hidden in the images of the James Webb Space Telescope.

Specific, These are six potential galaxies that arose very early in the universe’s history and are so massive that they should not be possible according to current cosmological theory, reports the journal Nature.

Each of the candidate galaxies could have existed at the dawn of the Universe, about 500 to 700 million years after the Big Bang, or more than 13 billion years ago. In addition, they are gigantic and contain almost as many stars as the present Milky Way.

“It’s crazy,” said Erica Nelson, co-author of the new study and associate professor of astrophysics at the University of Colorado. “You can’t expect the early universe to be able to self-organize so quickly. These galaxies should not have had time to form,” he added.

Nelson and colleagues, including first author Ivo Labbe of Swinburne University of Technology in Australia, published their findings on February 22.

The latest discoveries are not the first galaxies observed by James Webb, which launched in December 2021 and is the most powerful telescope ever sent into space. Last year, another team of scientists discovered four galaxies that likely formed from gas about 350 million years after the Big Bang. However, these objects were really tiny compared to the new galaxies, because they contained many times less mass of stars.

Researchers still need more data to confirm that these galaxies are as big as they appear, and that they go back that far. However, his preliminary observations offer a tantalizing glimpse into how Webb might rewrite the astronomy textbooks.

“Another possibility is that these are other types of strange objects, such as faint quasars, which would be equally interesting,” Nelson said.

Last year, Nelson and his colleagues from the United States, Australia, Denmark and Spain, including University of Valencia researcher Mauro Stefanon, formed a team to study the data sent back to Earth by James Webb.

Their latest conclusions were made as a result of the CEERS (Cosmic Evolution Early Release Science) telescope study. These images show a patch of sky near the Big Dipper, a relatively dim region of space, at least at first glance, first observed by the Hubble Space Telescope in the 1990s.

Nelson was looking at a postage stamp-sized portion of the image when he saw something strange: “fuzzy dots” of light that seemed too bright to be true. “They were very red and bright,” Nelson said. “We didn’t expect to see them,” he continued.

He explained that in astronomy, red light is often equivalent to ancient light. According to Nelson, the universe has been expanding since the beginning of time. As they expand, galaxies and other celestial objects move away, and the light emitted by them stretches. The more light is stretched, the redder it appears to human instruments. On the contrary, the light from objects approaching the Earth is more blue.

The team did the calculations and found that their ancient galaxies were also huge, containing tens to hundreds of billions of stars the size of the Sun, on the same level as the Milky Way.

However, these early galaxies probably had little in common with our own. “The Milky Way forms one to two new stars every year,” Nelson explained. “Some of these galaxies should have formed hundreds of new stars per year throughout the history of the universe,” he added.

Nelson and his colleagues want to gather much more information about these mysterious objects with the help of James Webb, but they had already seen enough to pique their curiosity. First, the calculations show that there shouldn’t have been enough normal matter at the time—the stuff that makes up planets and human bodies—to form so many stars so quickly.

“If even one of these galaxies is real, it will push the limits of our understanding of cosmology,” Nelson said.

The new discoveries are the culmination of a journey that began when he was in elementary school, he said. When she was 10 years old, she wrote an article about Hubble, the telescope that was launched in 1990 and is still operating, and she fell in love.

“Light takes a while to travel from the galaxy to us, which means you’re looking back in time when you look at these objects,” he explained. “The concept seemed so amazing to me that at that moment I decided it was what I wanted to do with my life,” he said.

The rapid pace of discovery under James Webb is very similar to those early days of Hubble, Nelson recalled. At the time, many scientists believed that galaxies began to form only billions of years after the Big Bang. But researchers soon discovered that the early universe was far more complex and fascinating than they had imagined.