Quasars emit primordial light. They are far away both in terms of time and distance. It is easy to confuse them with other astronomical sources of light, such as stars closer to Earth.
But when we detect them, they tell astronomers a lot about the earliest moments of the universe, knowledge that helps us learn more about our place in it.
The European Space Agency’s Euclid space-based telescope was launched in 2024 to map the universe. ESA has released images of the two most ancient quasars ever found.
They are just two of a series of 31 quasars that harken back to a time when the universe was just 670 million years old. This is within the first 5% of its current age.
“Before, we could only find a handful of the brightest ancient quasars, but Euclid lets us search much more efficiently across vast regions [the night sky] To capture very dim light. “This is a unique tool for quasar hunting,” says Daming Yang, lead author of a study about the new findings published July 6, 2026.
Quasar Hunting: An Archaeological Excavation of the Universe
The two oldest quasars identified in the new discovery are:
- EUCL J172902.75+641018.1
- EUCL J125308.55+705432.3
If you look at the image below, you will find decimal numbers next to the quasar names. These numbers indicate their respective redshifts, The measurement of the distance and motion of a light source in the universe relative to Earth.
Redshift is sometimes compared to the Doppler effect in sound – the idea that when you move toward or away from a sound, such as an ambulance siren, it changes in pitch. When it is moving towards you, you hear it at a higher pitch or frequency, and as you move away from it, you hear the same sound at a lower pitch or frequency. Higher and lower pitches are similar to bass sounds and treble sounds in music.
The difference is that redshift is related to light rather than sound. Think about these new quasars from the earliest moments of the universe – they are very far away from us. They have longer wavelengths, shifted to the red region of the spectrum. Hence, transferred again.
Unfortunately, there is no useful visual equivalent from everyday life to represent redshift.
But what’s really fascinating about these quasars is that, while we and they may have been in the same relative location over time, the light from those quasars gets stretched, or reddened, as the universe is expanding.
“This discovery doubles the number of quasars that we know of that are this ancient,” says Antonio La Marca, ESA Research Fellow in the Euclid team.
It took astronomers more than a decade to discover the first 10 quasars with redshifts of 7 or greater. The Euclid telescope has discovered more than this in a single year of operation.
Edited by: Derrick Williams