The Milky Way could be part of a much larger 'cosmic neighborhood' than we realized, challenging our understanding of the universe. Our galaxy may be situated within an expansive region of gravitational influences, known as a 'basin of attraction,' that's 10 times larger than previously thought.

The Milky Way galaxy could be part of a much larger cosmic structure than previously thought, according to a new study that challenges our understanding of the universe.

The research, published Sept. 27 in the journal Nature Astronomy, suggests that our galaxy may be situated within a vast region of gravitational influences, known as a "basin of attraction" (BOA), that's potentially 10 times larger than the currently recognized Laniākea supercluster.

"The Milky Way could be embedded in a much larger structure than we thought," study co-author Noam Libeskind, a cosmologist at the Leibniz Institute for Astrophysics Potsdam in Germany, told Live Science. "This is exciting because it means that our cosmic neighborhood could be much bigger than we realized."

To understand what a BOA is, it's helpful to think of the universe as a series of nested dolls, with smaller gravitational structures contained within larger ones. For example, the moon orbits Earth due to our planet's gravitational pull. Earth, in turn, orbits the sun along with the other planets in our solar system. Our solar system then orbits the supermassive black hole at the center of the Milky Way.

But the Milky Way isn't alone. It's part of a small group of galaxies called the Local Group, which includes the Andromeda galaxy and about 100 smaller galaxies. The Local Group, in turn, is part of a larger structure called the Virgo Cluster, which contains about 1,500 galaxies.

In 2014, astronomers discovered that the Virgo Cluster is part of an even larger supercluster of galaxies called Laniākea, which spans roughly 520 million light-years. At the time, Laniākea was thought to be the largest structure that had a gravitational influence on the Milky Way.

But the new study suggests that the Milky Way may be situated within an even larger region — possibly the Shapley Concentration, which is about 10 times larger than Laniākea.

To reach this conclusion, the researchers analyzed the velocities of more than 56,000 galaxies in the nearby universe. They then created a 3D probabilistic map that shows the likelihood of the Milky Way being influenced by different gravitational forces.

The results suggest there's a 60% chance that our galaxy is part of the Shapley Concentration, a massive region of space that contains several superclusters of galaxies.

However, the researchers caution that there's still a lot of uncertainty in these measurements. One of the main challenges is accurately measuring the velocities of distant galaxies, which is complicated by the presence of dark matter — an invisible form of matter that makes up about 85% of the universe's mass.

"The problem is that we can't see dark matter, but we know it's there because of its gravitational effects," Libeskind said. "This makes it difficult to accurately measure the velocities of galaxies, which in turn makes it hard to determine which gravitational forces are influencing them."

The researchers also note that our current surveys of the universe may not be extensive enough to fully capture these large-scale structures. "It's possible that there are even larger basins of attraction that we haven't discovered yet," study co-author Ehsan Kourkchi, an astronomer at the University of Hawaii, told Live Science. "We're like a person with giant eyes, but we can only see so far."

Despite these uncertainties, the study provides a new perspective on our place in the universe. If the Milky Way is indeed part of the Shapley Concentration, it would mean that our cosmic neighborhood is much larger than we thought.

This could have implications for our understanding of how galaxies form and evolve, as well as how matter is distributed throughout the universe. It could also challenge our current models of cosmic structure, which are based on the assumption that the universe is homogeneous and isotropic (the same in all directions) on large scales.

The researchers hope that future surveys, such as those planned with the upcoming Vera C. Rubin Observatory in Chile, will provide more precise measurements of galaxy velocities and help to refine our cosmic maps.

"As we improve our observational techniques, we may discover that the universe is even more complex and interconnected than we currently realize," Libeskind said. "It's an exciting time to be studying cosmology."

Image Credit: Alamy