Have you heard of quasars? They are supermassive black holes that exist in the center of galaxies, and although they are "black holes", they are the brightest astronomical objects in the universe, emitting hundreds and even thousands of times more light than an entire galaxy.

This is because these star monsters are very active and stay there in the center of the galaxies, "devouring" gas and cosmic dust. The black holes themselves do not emit any light, but as they draw mass into them, they expel super energetic jets of matter back into space, leading to the formation of a disc of material around them - and it is all this activity that generates the emission of light.

Cosmos Old Man

Now, a team of scientists has announced the discovery of the oldest - and hence farthest - quasar ever detected in the cosmos. The "bug", which is almost a billion times more massive than our Sun, is an extraordinary 13.1 billion light years away from us.

Illustration showing the oldest and most distant quasar in the universe (The Verge / Robin Dienel / Carnegie Institution for Science)

This means that this black hole formed only about 690 million years after the Big Bang and that the light it emitted took all these billions of years to get here. What's more, it also means that by observing quasar, scientists can actually observe what the universe was like just a few million years after its origin. Yes, dear reader, it is mind-boggling!

And how did scientists do to determine that this quasar is at such an absurd distance? They did it from something known as “redshift” - a concept that we at Mega Curious already explained in an earlier article (which you can access via this link), but which basically allows things like location and cosmic object composition are defined based on how the light waves emitted by them behave.

Cooler

Physicists believe that soon after the Big Bang, the universe consisted of a superheated soup of energetic particles that were expanding at an absurd speed. Then, as the particles separated from each other during this period of inflation, they "cooled" and combined into a gas composed of neutral hydrogen.

Another representation of a quasar (Wikimedia Commons / ESO / M. Kornmesser)

At this stage, the universe still had no light sources, such as stars and galaxies - which began to form millions of years after the Big Bang, after gravity acted on matter and caused it to condense, creating the astronomical objects. For when these first stars began to emerge, the energy released by them caused the neutral hydrogen to become ionized - and thus the photons began to travel freely through the cosmos.

Well, based on such a redshift, scientists realized that the hydrogen present in the quasar, instead of being ionized, appears to be neutral. As a result, they concluded that much of the material that makes up the black hole comes from the time when the universe was just a little baby - and it was just a dark, half-empty place.

So far, astronomers have identified between 20 and 100 quasars as bright or nearly as far away as the one now detected, and with the construction of more powerful telescopes, new black holes are expected to be found. In addition, as well as being a super interesting discovery for astronomy lovers, identifying this quasar old man can help scientists catch a glimpse of how the universe was in the early stages of its formation and better understand how it evolves and how stars, galaxies and other comic objects originated.