The Quipu is a giant cosmic structure consisting of thousands of galaxies. It first became known after the publication of a study by an international group of scientists in early February 2025. At the time, news reports were full of claims that it was the largest structure known to mankind. But is it so? Let’s find out together.
The space structure of Quipu
In February 2025, it was reported that the largest structure known to mankind was discovered in space. It was named Quipu, in honor of the rope writing system of South America.
Earthly quipu is a thick rope to which many other, much shorter ones are tied. Information is encoded through the color of these fragments, their length, and the knots that are tied to them.
The open structure is indeed similar to them. It resembles a ribbon stretching at least 1.3 billion light-years, with much shorter ribbons attached to it. Its total mass is 200 quadrillion times that of the Sun.
All of this is impressive, so it is not surprising that Quipu was quickly recognized as the largest structure in the entire Universe. However, if you ask about large structures in space, you will find that there are, for example, the Sloan Great Wall, which is 1.38 billion light-years long, or the giant arc, 3.3 billion light-years in diameter, not to mention the Hercules–Corona Borealis Great Wall, which generally stretches for 10 billion years, although its unity as a structure remains debatable.
The scale of the Universe
So what about the largest known structure – is it a fake? To understand this question, we need to understand what scale we are talking about when we talk about something larger than a supercluster of galaxies.
As a starting point, we should take our Galaxy. It is a disk with a diameter of about 100 thousand light-years, surrounded by an extended spherical halo. At a distance of about 2.2 million light-years from it is another, slightly larger disk, the Andromeda Galaxy.
Together with several dozen other much smaller star systems, they form the Local Group, a gravitationally bound system with a size of 7-10 million light-years. However, in space there are close systems of galaxies of much larger size – clusters. A typical example is the Virgo cluster, located at a distance of about 48 million light-years from us in the direction of the constellation of the same name. There, inside a sphere with a diameter of about 15 million light-years, are more than 2000 galaxies. Of course, at such a density, they actively interact with each other, and the dark matter halo, if they have one, must be shared.
Individual groups and clusters of galaxies can combine into much larger structures –superclusters. Gravitational forces in them do not affect all their members as much, but the size of these structures is truly gigantic.
An example of this is the Virgo supercluster, which includes the cluster of the same name, our Local Group, and at least a hundred other groups and clusters. The total number of individual star systems in it can reach 30 thousand. Scientists do not know the exact number, because it is very difficult to calculate even approximately. The Virgo Supercluster is about 110 million light-years long, but about 60% of the galaxies in it are concentrated in a layer ~10 million km thick. In other words, it’s shape resembles a thread, a ribbon, or an elongated sheet.
And the other 10 million superclusters that exist in the visible Universe have approximately the same shape. It should be remembered that it is 93 billion light-years old, i.e., more than 800 times the maximum size of the Virgo supercluster. All of this suggests that these pieces of “threads” can and should form complexes of a larger order, but several problems arise here. The first is that there is such a thing as a cosmological principle. On a large scale, the distribution of matter should be homogeneous. This is indicated by the fact that relict radiation and other traces of the early epochs of the Universe’s existence do not depend on the direction in which we study them when looking from Earth. And the distant galaxies are more or less evenly distributed. According to scientists’ theoretical calculations, orderly structures over 1.2 billion light-years long should not exist.
The second problem is that it is quite difficult to see structures larger than the Virgo supercluster. They are too large and must be even more dispersed than lower-level structures. That is why every case when we manage to discern some even more grandiose structure behind hundreds of thousands of individual galaxies, each of which is itself a system whose size is almost beyond human imagination, is the result of a unique study.
For example, the Virgo supercluster, along with several others, is part of a larger formation called Laniakea, which means “vast heavens” in Hawaiian. This structure is shaped like a feather and is about 520 million years old. This sounds very similar to how Quipu is described, and for good reason. All of the discovered structures larger than the supercluster are shaped like threads, feathers, or quipu. The largest of them are called filaments. For example, Laniakea is part of the Pisces–Cetus Supercluster Complex, and it stretches for 1 billion light years.
There are also larger structures, but they are usually billions of light years away from us, and it is mostly possible to assess whether galaxies are located there in some special way in a rather indirect way. Therefore, when we talk about something that is more than a billion light-years away, it is still difficult for scientists to say whether it is a real structure, like the Milky Way, or whether it is just a pile-up of a huge number of unrelated objects in which our brains are trying to catch some structures. There is no definitive answer to this question.
So what is Quipu?
After all this, it’s worth taking a closer look at what the researchers found in February 2025. First of all, they took a survey of the entire sky in ROSAT X-rays and extracted information about galaxies and clusters that have a redshift of 0.03 to 0.06. This value depends on the distance between us and the star system. Thus, the distribution of galaxies was studied at a distance of 400 to 800 million light-years from us.
At the same time, although information was collected from all over the sky, a fairly wide band that coincides with the plane of the Milky Way remained empty. This is the so-called avoidance zone. The interstellar hydrogen in our Galaxy generates strong radiation that makes it impossible to see what is behind it. There are ways to look through it, but they were not used in this study.
Of all the data that was collected, scientists were interested in the position of zones of high density of galaxies similar to the Virgo supercluster. There were several dozen of them, and among them there were practically none that are part of the Laniakea or the Pisces–Cetus Supercluster Complex. That is, scientists have seen who our closest neighbors are.
And it’s not as if scientists knew nothing about it before that. The Shapley Supercluster and the Hercules Supercluster have been known for almost a century. The Serpens-Corona Borealis and Sculptor-Pegasus superclusters were also discovered earlier.
However, the study showed the presence of another large group of superclusters that seemed to form a chain stretching along the avoidance zone and eventually hiding in it. This is Quipu, which is essentially very similar to the other four megastructures mentioned above, as well as Laniakea, but larger than them.
It is worth mentioning that in fact there is another giant structure in the vicinity of Laniakea that is very similar to it, but was considered separately in the study.
We are talking about the Vela Supercluster. This gigantic structure, whose size is comparable to Quipu or the Pisces–Cetus Supercluster Complex, is hiding from us in the avoidance zone. We know for sure that it is there, thanks to research in the infrared part of the spectrum.
The authors of the study admit that it could be almost as large as Quipu and close enough to it. However, they categorically reject the possibility that they are parts of the same whole.
Thus, the statement about the outstanding size of Quipu is correct, but only partially. The 800 million light-year diameter sphere covered in this paper is the area of space in which solar radiation has been spread since the emergence of multicellular life on Earth. So, in this gigantic piece of space, which contains millions of galaxies, there is no structure larger than Quipu. But in the vast Universe outside this bubble, there are much larger things. Scientists have only just begun to learn what kind of structure all these threads are woven into.
