Discovered in the 1970s, the Great Attractor has remained a mystery despite many attempts to study it. The searches collide with the observation direction, near the plane of our Milky Way, where he is obscured by the large quantities of gas and dust present.
A common homework exercise was to draw our Solar System in model form. Thanks to this exercise, we know that our planetary system is a group of objects revolving around one stella. But in those models the sun was static, floating motionless in space. However, astronomers have pointed out for decades that the Solar System, and especially our galaxy, the Milky Way, are traveling across the vastness of the universe at about 600 kilometers per second. And it has long been known that this journey has a destination. The discoveries made in the ’70s by a group of astronomers made it possible to determine the existence of a “great force” whose origin would be the destination of the journey that the galaxy is making even now. This force was called the “Great Attractor”. “Our galaxy is heading in the direction of something we can’t see clearly. The focal point of that movement is the Great Attractor, the product of billions of years of cosmic evolution.”, explains cosmologist Paul Sutter, professor of astrophysics at Stony Brooks University in New York in an interview with BBC Mundo. And, despite the impressive speed with which our galaxy travels, it will most likely fail to reach the destination of the Great Attractor. “We will never reach our destination because, in a few billion years, the accelerating force of dark energy will destroy the universe.”Sutter explains. Dark energy, as NASA explains, is a mysterious force that permeates the cosmos and accelerates the expansion of the universe. This results in galaxies moving further and further away from each other, until billions of years from now the structure of the universe as we know it will break down. Therefore, understanding the effects of the Great Attractor has to do with striving to know the structure of the universe. “As part of the study of space, it is very important to know how it is organized, because it is organized by structures that have certain dimensions and knowing each of them and their size helps a lot in this effort”. Carlos Augusto Molina, a Colombian astrophysicist who works at the Bogota Planetarium, explains to the BBC.
As space exploration has progressed, largely thanks to the launch of the Hubble telescope in the second half of the 20th century, astronomers have faced the challenge of somehow organizing everything that they saw. A kind of map began to be drawn and, obviously, one of the fundamental points was knowing where in the universe our Solar System and our galaxy were. “In the 70’s we started studying the motion of our Solar System, our galaxy, and we compared it to the motion of other nearby galaxies and everything seemed to go in the same direction as the expansion of the universe“, explains Sutter. “However, astronomers began to notice something curious: there seemed to be a vague directionality to this expansive motion, as if all the galaxies near us were also heading towards the same focal point.“, he adds.
For many astronomers, this “direction” had to do with flaws in the observations or other factors leading to one misreading of information they were receiving. But in the meantime the telescopes were improving their technologies more and more and, around 1986, science was able to determine that indeed the closest galaxies, including ours, are heading towards a common direction. “With these new instruments, astronomers are able to determine not only that we were heading towards a concentration of matter, but also how fast we were doing so. In other words, they were able to establish with great certainty what it was” – underlines Molina. In this sense, although it cannot be determined exactly, one of the main theories points to the fact that the Great Attractor is a large structure of dark matter located within the supercluster of galaxies known as Heaven and that it has the ability to attract galaxies in a radius more or less than 300 million light years away. Dark matter is another of the enigmatic components of the universe. It is a type of matter that cannot be observed, one can only guess that it exists due to the gravitational effect it exerts on objects in the cosmos. This large concentration of matter pulling galaxies has been called the “Great Attractor,” which is located about 200 million light-years from Earth. One reason Sutter has dedicated himself to studying more about the Great Attractor is that despite advances in astronomical observation, this superstructure remains a mystery. The Great Attractor is located about 200 million light years from our galaxy. “One of the big drawbacks of knowing more about the Great Attractor is that it is in a very awkward location: totally on the opposite side of our galaxy“, points out. “When we try to observe there is a lot of noise: many stars, planets, nebulae in a way that does not allow a more complete analysis of this force that attracts us“.
It’s not a black hole
Both Sutter and Molina are clear that the Great Attractor is not a black hole, emphasizing that it is, rather, a gravitational anomaly. “It’s a completely different force and there is no connection to black holes in the universe“says Sutter. The truth is, experts have spotted other similar anomalies elsewhere in the universe with a similar function: dragging galaxies along. “Knowing this helps us in a fundamental task to understand the universe: how it is composed of these structures that we classify or hierarchize according to their gravitational capacity“, says Molina. For the scientist, the “mapping” of the universe is achieved by learning more about how these areas interact with other forces, such as light or gravity. “Knowing this structure allows us to compare how processes such as the interaction with light – or not – or its density occur in similar structures in other galaxies of the universe”. Another important aspect is that it allows us to study the “future” of our space environment. “Knowing how fast our galaxy is moving and where it is going allows us to think or study aspects of how it will behave in the future.”Sutter notes. However, while we know from these developments the fate of this journey the galaxy is on, we also know that Earth or our Solar System may very well not be able to see the end. “There’s another very powerful force in the universe that we call dark energy, which is the exact opposite of gravitational: instead of pulling, it pushes.”dice Sutter. “For this reason, when we really get close to the Great Attractor in a few million light years, this dark energy, about which we know very little, will have an effect on this journey, which is most likely the destruction of everything in existence.”- concluded the scientist.