- Alejandro MillanValencia
- BBC News World
21 minutes ago
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There are many forces at work in the universe that we do not yet know about, such as dark energy.
A common exercise in school homework was to represent our solar system in the form of a model.
Thanks to this exercise, we know that the solar system is made up of a series of planets revolving around the great golden star. But in these models, the sun was static, floating in space.
However, astronomers have been pointing out for decades that the solar system, and in particular our galaxy, the Milky Way, is moving through the vast expanses of the universe at a speed of about 600 kilometers per second.
And we have known for a long time that this journey has a goal.
Discoveries by a group of astronomers in the 1970s revealed the existence of a “great force” the source of which would be the destination of the galaxy’s current journey.
This force is called the “Great Attractor.”
“Our galaxy is moving toward something we can’t see clearly. At the heart of this movement is the Great Attractor, the result of billions of years of cosmic evolution,” cosmologist Paul Sutter, professor of science, told BBC Mundo. Astrophysics at Stony Brooks University in New York.
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Image of the Great Attractor site taken with the Hubble Telescope.
And despite the impressive speed at which our galaxy is moving, it will likely never reach the destination set by the Great Attractor.
“We will never reach our goal because in a few billion years the accelerating force of dark energy will destroy the universe,” says Sutter.
Dark energy, NASA explains, is a mysterious force permeating the cosmos and accelerating the expansion of the universe.
This means that the galaxies will continue to move apart until, billions of years from now, the structure of the universe as we know it is destroyed.
Understanding the action of the Great Attractor is therefore part of the quest to understand the structure of the Universe.
“When exploring the universe, it is very important to know how it is organized, why it is made up of structures with certain dimensions, and knowing each of them and their dimensions helps us a lot in this endeavour,” says Carlos Augusto Molina , a Colombian astrophysicist who works at the Bogotá planetarium told BBC Mundo.
As space exploration advanced, thanks largely to the Hubble telescope launched into space in the second half of the 20th century, astronomers were faced with the challenge of somehow organizing everything they saw.
Some sort of map began to be drawn, and of course one of the most important points was knowing where our solar system and galaxy are in the universe.
“About the 1970s, we began studying the motion of our solar system and galaxy and comparing it to the motion of other nearby galaxies. Everything seemed to be going in the same direction, which is the expansion of the universe,” says Sutter.
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Our galaxy, the Milky Way, is on its way to where the Great Attractor is located.
“However, astronomers began to notice something odd: There seemed to be a vague directionality over this expansive motion, as if all the galaxies near us were also heading towards the same focus,” he adds.
For many astronomers, this “directionality” was related to errors in the observations or other factors that contributed to a misinterpretation of the information received.
But telescopes continued to improve their technologies, and by 1986 science was able to determine that the nearest galaxies, including ours, were heading in a common direction.
“With these new instruments, astronomers could tell not only that we were heading towards a concentration of matter, but also at what speed we were doing so. In other words, they could tell what it was with a high degree of certainty,” says Molina.
While this cannot be pinpointed, one of the main theories along these lines posits that the Great Attractor is a large dark matter structure residing in the supercluster of galaxies known as Laniakea that has the ability to attract orbiting galaxies of about 300 million light years.
Dark matter is another mysterious part of the universe.
It is a type of matter that we cannot observe but only suspect that it exists because of the gravitational effect it exerts on objects in the cosmos.
Dubbed the “Great Attractor,” this large assemblage of matter that brings galaxies together lies about 200 million light-years from Earth.
One of the reasons Sutter is dedicated to continuing to study the Great Attractor is that despite advances in astronomical observation, this superstructure remains a mystery.
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The Great Attractor is about 200 million light years from our galaxy.
“One of the big downsides of knowing more about the Great Attractor is that it’s in a very uncomfortable position: completely opposite our galaxy,” he says.
“When we try to observe, there is a lot of noise: many stars, planets, nebulae on the way, which do not allow a more comprehensive analysis of this force that pulls us.”
It’s not a black hole
Both Sutter and Molina are aware that the Great Attractor is not a black hole and point out that it is a gravitational anomaly.
“It’s a very different force and there’s no connection to the black holes in the universe,” says Sutter.
The truth is that by being able to pinpoint it, it was also possible to pinpoint that there were other similar anomalies in other parts of the universe that would have a similar function: attracting galaxies.
“This knowledge helps us with a fundamental task in understanding the universe: how it is composed of these structures, which we classify or prioritize according to their gravitational capacity,” explains Molina.
For Molina, “mapping” the universe is accomplished by learning more about how these areas interact with other forces, such as light or gravity.
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The Great Attractor takes us on a journey that we may not reach the ultimate destination.
“If we know this structure, we can compare how processes such as the interaction with light – or its absence – or its density take place in similar structures in other galaxies in the universe,” he adds.
Another important aspect is that it allows us to study the “future” of our space environment.
“If we know how fast our galaxy is moving and where it’s going, we can think about or study aspects of its future behavior,” notes Sutter.
While we know the fate of this galaxy journey through these advances, we also know that Earth or our solar system may not see the end.
“There’s another very powerful force in the universe that we call dark energy, which is the complete opposite of gravity: instead of pulling, it pushes,” explains Sutter.
“Because of this, if we get really close to the Great Attractor, which is a few million light years away, this dark energy that we know very little about will have an impact on this journey that will most likely lead to destruction.” everything we know,” concludes the scientist.