Scientists have found the oldest twin galaxy of the Milky Way – it has broken ideas about the Universe

Scientists at the European Southern Observatory (ESO) using the ALMA radio telescope have made a surprising discovery that challenges our understanding of the evolution of galaxies. Just 700 million years after the Big Bang, they discovered a galaxy with a structure similar to our Milky Way. This is the most distant spiral galaxy with a rotating disk in the entire history of observations. She simply shouldn’t have been there.

Image source: ESO

The modern theory of the evolution of stars and galaxies believes that from the chaos of mergers of these objects, a clear and ordered structure with a rotating disk will emerge only after several billion years of evolution. Look at the Milky Way! It took this galaxy 13.8 billion years to achieve harmony in geometry and motion. Thanks to the James Webb Telescope, discoveries began to disrupt the harmony of theories. For example, a year ago it became known about the “twin” of the Milky Way, discovered 2 billion years after the Big Bang. The new discovery revealed an even more glaring oddity. A mature galaxy with a rotating disk was discovered another 1.3 billion years earlier.

The strange galaxy was named REBELS-25. Strictly speaking, it was not discovered in ALMA (Atacama Large Millimeter Array) data today. But since the discovery of REBELS-25, scientists have collected enough evidence to be convinced that they are right: REBELS-25 is what it seems. Additional research has collected evidence that this galaxy is the outermost rotating disk and an advanced structure with a bar of stars at the center and spiral arms. This colossal structure could not and should not have become what we see it at the time of its observation.

«The observation of a galaxy so similar to our own Milky Way, where rotation dominates, challenges our understanding of how quickly the galaxies of the early Universe evolve into the orderly galaxies of the modern cosmos,” said Lucie Rowland, a doctoral student at Leiden University and first author of the study.