The great attractor: cosmic mystery and imminent doom

Table of contents:

The great attractor: cosmic mystery and imminent doom
The great attractor: cosmic mystery and imminent doom

Over the past few decades, our understanding of the universe has expanded significantly. However, space still holds many secrets, and the Great Attractor is one of them.


About 40 years ago, astronomers figured out that the galaxy is moving through space much faster than anticipated. So, the Milky Way rushes through space at a speed of 2.2 million kilometers per hour - 2.5 thousand times faster than an airliner, 55 times faster than the speed of escape from the Earth and two orders of magnitude higher than the speed of escape from the Galaxy itself. However, where this speed comes from is not clear.

According to the Big Bang theory, every point in the universe should be evenly removed from every other point. That is, galaxies around the Milky Way should move away from it at the same speed, and in the frame of reference of the Galaxy itself there should be no proper motion.

The proper motion can arise from such accumulations of matter as massive galactic clusters. The additional gravitational effect of the galaxy cluster can slow down or even reverse the expansion of the Universe in the immediate vicinity of a certain frame of reference.

However, no such clusters are observed in the direction of the Milky Way. In the vicinity of the Galaxy there are many galaxies and abundant radiation observed by X-ray telescopes, but there is nothing that looks large enough to explain the observations.


What do we see? Could it be a super-dense cluster of dark matter? Or is the modern theory of the origin of mass and motion wrong? Astronomer Alan Dressler of the Carnegie Institution called this missing concentration of matter the Great Attractor.

Hidden attractor

Is the Milky Way capable of sweeping through space like a spinning disk, blocking out the source of a distant gravitational attractor? Could there be a supermassive galaxy cluster (which should be equivalent to 10 thousand Andromeda galaxies), which we cannot see due to the dense layer of dust inside the disk of the Galaxy?

In the late 1990s, a team of scientists began using a then-innovative instrument mounted on the Parkes Telescope in New South Wales, the Parkes Multibeam Receiver. Its unique sensitivity and field of view allowed for an unprecedentedly sensitive radio survey of the sky.


These studies were made possible by tuning the receiver to a neutral hydrogen radio link. Despite the fact that this is a weak line, the sensitivity of the receiver made it possible to register thousands of galaxies in "blind" sky surveys. Moreover, on radio waves, radiation travels directly through the dust layer in the Milky Way. In fact, the Galaxy becomes invisible.

The HI Parkes All-Sky Survey (HIPASS) in the neutral hydrogen line helped observe the entire southern sky for the first time. In addition, HIPASS was the first sensitive survey of the sky for extragalactic hydrogen ever carried out with a telescope. However, nothing unexpected or unusual has been found outside the Milky Way.

Scientists have concluded that more careful observation is needed. Theoretical models can only be challenged if nothing is found within 200 million light years.

Thus, a series of detailed observations of the local universe outside the disk and bulge of the Milky Way were carried out - again, using the Parks telescope.

There is something there

These studies were completed by the mid-2000s. Due to the complexity of analyzing radio data in the Milky Way (caused by additional noise from cosmic rays), they were processed only by 2016.

Within five degrees of the Milky Way's disk, 883 galaxies have been discovered and another 77 in two parts of the northern region of the Galaxy, visible from the Parks telescope. Only a small part of these galaxies had previously optically observed a redshift, which means that the distance to them was estimated. The Great Attractor is located in that area, although it was not possible to find it directly.


And although it has long been known that there is a certain anomaly in that area, everything began to take on specific features only after these studies. As a result, the location and strength of this excessive density was revealed quite recently.

Is he so great

Work carried out at the Parks Observatory has helped open up new galaxies, galaxy clusters and even new strands of the cosmic web. However, with regard to the immediate gravitational anomaly, instead of finding out more, the observations only exacerbated the mystery surrounding it. The problem is that the excessive density is on the other side of the Milky Way's disk. Between the Great Attractor and us is a huge cluster of stars, cosmic dust and gas.

All this makes it difficult to consider the light emanating from that area, and makes it impossible to observe and study it. This area has been called the zone of avoidance, and the Great Attractor is believed to be right in the middle of it. From time to time, something manages to get through this area. X-ray and radio astronomers are just beginning to observe what is on the other side, but so far the picture is very cloudy and, to put it mildly, incomplete.


Destruction course?

The only thing astronomers know for sure is that the Milky Way and other galaxies in our supercluster are heading towards the Great Attractor. No one really knows what this might mean or if our planet is in danger. Astronomers say it will take them several more years to learn more about this anomaly. Some experts do not consider this a threat, while others argue that all galaxies and clusters are merging into larger and larger superclusters and so the Universe will come to its end - this is part of the Big Compression, which could theoretically follow the Big Bang.

However, don't be upset. Even if the Great Attractor does not pose a threat, we are faced with such problems as climate change, a possible collision with the Earth of a giant astroid, or a supervolcano eruption, which will cause a volcanic winter and possibly kill the human race. Even if we survive in all of the above scenarios, we will face the death of the Sun in seven to eight billion years, the collapse of the Higgs field, or the heat death of the Universe. Nevertheless, we can safely say that the Great Attractor is the most mysterious scenario of the apocalypse of all.

Popular by topic