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In this activity, students investigate the large-scale architecture of the Local Universe through the exploration of a 3D tactile model that represents galaxy clusters, superclusters, filaments, and cosmic voids. Rather than focusing on individual galaxies, learners are guided to recognize patterns and connections that reveal the web-like structure of matter on the largest observable scales. By examining the hierarchical organization of galaxies within clusters and superclusters, students develop an understanding of how gravity — together with dark matter — drives the formation and evolution of the Cosmic Web. The activity also invites them to reflect on our own location in this vast structure and to explore large-scale cosmic motions, including the gravitational influence of the Great Attractor and the Shapley Supercluster.Using the 3D models developed within the A Touch of the Universe project, students analyze how matter is distributed across space and how immense gravitational structures shape cosmic dynamics. Through tactile exploration, guided inquiry, and mathematical interpretation, they build a deeper understanding of the forces governing the Universe. The activity is designed to be inclusive and hands-on, making complex cosmological phenomena accessible to all learners, including those who are visually impaired.
A cosmic spider web
Following the Big Bang, dark matter started to concentrate by the effect of gravity into filament-like structures that attracted also ordinary matter. The growing concentration of ordinary matter within these filaments led to the formation of the first galaxies. Because the matter density—and therefore, gravity—was greatest at the filament intersections, galaxy formation was more intense in these regions. This gave rise to enormous galaxy superclusters, which contain hundreds of galaxy clusters, each holding hundreds to thousands of galaxies. These superclusters kept growing by also attracting galaxies formed in the less dense environments along the filaments.
The complex network of filaments of dark matter, gas and galaxies, with clusters and superclusters of galaxies at the points where several of these filaments meet is called the "Cosmic Web". The filament structure surrounds large regions which are called ‘voids’, because most of the matter that was initially in them has been pulled up to the filaments by gravity, thus leaving these regions almost empty.
The filaments are made up of gas, ordinary matter and dark matter. Dark matter constitutes about 75% of all the matter content of the Universe but we still do not know what the dark matter is made of. Some possible candidates are microscopic primordial black holes, or mysterious particles called WIMPS that have not been detected yet. The study of these filaments, the way galaxies form inside them and how they move and behave under the gravitational pull of dark matter will help astronomers to discover what it really is.
Only recently large sky surveys have allowed astronomers to identify galaxy superclusters. Astronomers estimate that there are about 10 million superclusters in the region of the Universe that we can observe. The observable Universe is a spherical region of space around us from which light has had enough time to reach Earth since shortly after the Big Bang. We cannot observe what is beyond that spherical frontier because the light of the galaxies and objects lying beyond has not had enough time to travel to us.
Galaxy superclusters are among the largest structures in the Universe, and they are becoming bigger as they participate in the general expansion of the Universe. That is, the distance between the individual clusters inside them is increasing. On the other hand, galaxy clusters are not expanding and hold their galaxies together by the force of gravity. Our home supercluster, called Laniakea, is an exception as it does not seem to be expanding, thanks to the powerful gravitational grasp of the Great Attractor.
Image: The Local Group’s location within the Virgo Supercluster as part of the larger Laniakea Supercluster. Credits: Andrew Z. Colvin - Own work
Everything around is moving, including us!
Our galaxy resides in what we call the Local Group of Galaxies. It contains about 50 galaxies. The Local Group is embedded in the larger Virgo galaxy cluster, which in turn is part of the Laniakea supercluster. Laniakea is estimated to comprise about 100 000 galaxies (including our Milky Way) which are gathered in about 300 to 500 known galaxy clusters and groups. Lanikea's size is about 520 million light years.
Laniakea is a Hawaiian word that means "immense heaven". "Lani" means heaven and "Kea" means immense.
The Great Attractor is a region, located 150-250 million light years from Earth, of immense gravitational force due to its huge mass, equivalent to that of tens of thousands of galaxies. It is the gravitational center of Laniakea. The Milky Way and other galaxies around us are being pulled towards this region, so this is how it got its name. We are travelling at a speed of 600 km/s towards the Great Attractor!
We do not know well what the Great Attractor is, because it lies behind the center of our galaxy. The enormous amount of dust and gas in the Milky Way's center does not allow us to observe it. But we know of its existence because we can measure the movement of our galaxy and others towards it.
Even more, the Great Attractor and the galaxies it drags along with it are moving towards the Shapley supercluster, which is 650 million light-years away from us. This structure contains more than 8000 galaxies, that are home to stars equivalent to more than 10 million billion suns. Everything around us is moving towards the Shapley supercluster as it is the most massive galaxy cluster within a billion light years.
Image: Laniakea Supercluster of galaxies shown in a computer-generated visualization, where green areas are rich with white-dot galaxies and white lines indicate motion towards the supercluster center. An outline of Laniakea is given in orange, while the blue dot shows our location. Credits: R. Brent Tully (U. Hawaii) et al., SDvision, DP, CEA/Saclay - https://apod.nasa.gov/apod/ap140910.html
The 3D model
To better illustrate the intricacy of the Cosmic Web and to make it accessible also to visually impaired publics, we will use a 3D model developed by our group as part of the "A Touch of the Universe" 3D astronomy model collection. In the 3D model in Fig 1 we represent the region of the Cosmic Web where we live, so it includes Laniakea, the galaxy supercluster where the Milky Way resides. The Milky Way would be at the center of the model, but the model scale does not allow us to represent it. It is possible, though, to identify several galaxy superclusters, cosmic objects encompassing thousands of galaxies, which we have represented as smooth, irregular solid shapes that look like large beans. In the Braille version of the model, each supercluster has been marked with a letter in the Braille alphabet corresponding to the initial of the supercluster name: Pavo-Indus (i), Hercules (h), Shapley (s), The Great Attractor (g), Lepus (l), The Funnel (f), Perseus-Pisces (p), and Coma (c).
Astronomers consider that the Great Attractor, Coma and Pavo-Indus superclusters are also part of Laniakea, as does Virgo, where the Milky Way lies. The superclusters have been hand-colored in the "labelled" pdf to make it easier to identify them visually.
The filaments that connect two superclusters are named after the clusters themselves: the Hercules-Shapley filament lies between the Hercules and Shapley superclusters, the Shapley-Lepus filament connects the Shapley and Lepus superclusters and the Perseus-Coma filament, links the Perseus and Coma superclusters. We have left holes in the filaments to allow the user to see and touch the superclusters embedded in them.
The portion of the universe represented in the model contains about 1 million galaxies. The data were obtained from observations made in all directions by telescopes on Earth. Therefore, our planet is placed approximately at the center of the model.
The whole observable Universe is about 200 times the size of this model. The observable Universe is the spherical region of space around us from which light has had enough time to reach Earth since the Big Bang. We cannot observe what is beyond that.
Image: the 3d model of Laniakea
Numerical Curiosities
Laniakea, the galaxy supercluster we live in, is about 520 million light years. We would need 520 million years to travel from one end to the other at the speed of light in vacuum, the fastest speed in the Universe!
The extent of the whole model is beyond 1000 million light-years. One light-year is equal to 9.46 trillion, or 946 followed by 10 zeroes, kilometers! The fastest speed reached by a spacecraft, NASA's Parker Solar Probe, is 192.22 km/s. Therefore, Parker Solar Probe would take 1,6 trillion (or 16 followed by 11 zeroes) years to go from one end to the other, much longer than the age of the Universe itself!
The Shapley supercluster contains stars, black holes, dust and gas residing in about 8000 galaxies. Their mass is equivalent to 50 quadrillion times the mass of our Sun or 50x1015 using scientific notation. This is 50 followed by 15 zeroes! If you count one number per second, it would take you 1600 million years to count to 50x1015!
Getting ready:
Activity (ages 10-12):
Activity (ages 12-16):
Activity (ages 16-19+):
Ages 10-12:
Ages 12-16
Ages 16-19+
Ages 8-12:
Natural Sciences
Ages 12-16:
Physics and Natural Sciences
Ages 16-19+:
Physics and Astronomy
Mathematics
Applying scientific notation in real contexts
