Astronomers say they have solved an extraordinary problem that challenges our understanding of how the universe evolved: the spatial distribution of faint satellite galaxies orbiting the Milky Way. These satellite galaxies display a strange alignment; They appear to lie on a wide, thin, rotating plane called the “satellite plane.”

This seemingly unlikely arrangement has baffled astronomers for over 50 years, and has led many to question the validity of the Standard Cosmological Model, which attempts to explain how the universe came to be what it is today. Now, new research led by the Universities of Durham in the UK and Helsinki in Finland has found that the plane of the satellite is a cosmological quirk that will resolve over time as stellar constellations change.

Their research resolves the problem that satellite drones pose for the Standard Model of Cosmology. This model explains the formation of the universe and how the galaxies we see now gradually formed inside clumps of cold dark matter, the mysterious matter that makes up about 27% of the universe.

The Milky Way’s moons appear to lie in an incredibly thin plane running through the galaxy, and oddly enough, they also spin in a coherent and long-lived disk. There is no known physical mechanism that could make satellites fly. Instead, it was thought that satellite galaxies should be arranged in a roughly circular configuration that followed dark matter.

Since the discovery of the satellite plane in the 1970s, astronomers have tried in vain to find similar structures in realistic supercomputer models that track the evolution of the universe from the Big Bang to the present. The inability to explain the moons’ positions has led researchers to believe that the cold dark matter theory of galaxy formation may be wrong.

But this latest study has seen astronomers use new data from the European Space Agency’s Gaia space observatory. Gaia maps the Milky Way in six dimensions, providing precise measurements of the positions and movements of nearly a billion stars in our galaxy (about 1% of the total) and satellite systems.

This data allowed scientists to project the orbits of satellite galaxies into the past and future, and see how the plane formed and dissolved over a few hundred million years – in the blink of an eye in cosmic time. The researchers also looked to new, specially designed cosmological simulations for evidence of satellite planes.

They noticed that previous simulation-based studies made virtual satellite systems appear much more rounded than real systems, disregarding the satellites’ distance from the center of the Galaxy. Taking this into account, they found several virtual Milky Ways with a satellite galaxy plane very similar to that seen with telescopes.

The researchers say this removes one of the main objections to the plausibility of Standard Model cosmology and means that the concept of dark matter remains a cornerstone of our understanding of the universe. Co-author of the study, Professor Carlos Frank, Professor of Fundamental Physics at the Institute of Computational Cosmology at the University of Durham, England, said: “The strange arrangement of the Milky Way’s satellite galaxies in the sky has puzzled astronomers for decades.

“But thanks to the amazing data from the Gaia satellite and the laws of physics, we now know that the plane is just a matter of random alignment, just like the constellations of the stars in the right place at the right time. .

“We were able to address one of the main unresolved problems of the cold dark matter theory. It continues to provide a highly accurate description of the evolution of our universe.”

Lead study author Dr Till Savala, from the University of Helsinki, said: “The satellite plane was really impressive.

“Perhaps it is not surprising that a puzzle that has been solved for nearly fifty years requires a combination of methods and an international team to come together to solve it.”