The cosmic voids and supervoids, the great dark deserts of the universe

If you ask anyone what part of the universe is the darkest and most terrifying, they will most likely tell you black holes.

TON 618, a cosmic object whose existence defies the limits of human understanding
Sedna, the mysterious reddish world that takes more than 11,400 years to orbit the Sun

However, there are regions of the universe that are no less fascinating. I'm referring to the cosmic voids and supervoids, which are areas of the universe with a very low density of galaxies. If we were to compare these areas to a place on Earth, we could say that the voids and supervoids are like the deserts of the cosmos, enormous dark areas that separate different neighborhoods of galaxies.

Cosmic voids and supervoids were discovered in 1978, and thanks to space telescopes, we have learned that they are not actually as empty as their name suggests, just as is the case with the deserts on our small blue planet. The Local Void, which has been discovered in 1987 and is the closest to us, possibly extends between 150 and 230 million light-years. NGC 6503, known as the "Lonely Galaxy", is on its edge. In May 2020, NASA noted that within that Local Void is the dwarf galaxy KK 246, the only one that has been definitively identified within that dark region, in which there are 15 other galaxies provisionally identified.

The difference between voids and supervoids is that the former have a low density of galaxies and can, at most, extend over a few hundred million light-years. Supervoids would be enormous regions, up to billions of light-years across, with an extremely low density of galaxies. They are the great dark deserts of the universe, where the sky would appear almost completely empty if we could reach their interior. The largest known supervoid is the Eridanus Supervoid or CMB Cold Spot, extending over 1 billion light-years and located between 6 and 10 billion light-years from Earth. Kurzgesagt has published a very interesting video on this topic:

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Main image: Kurzgesagt.