The Euclid Space Telescope Has Found 31 New Ancient Quasars, Including the Most Ancient One Ever Found

Euclid is only 1.5 years into its Euclid Wide Survey and has found 31 new quasars from the Universe's first 800 million years. The science-journalism coverage adds useful context, while the strongest evidential footing still comes from the underlying data, papers or institutional documentation.

That matters because astrophysics becomes persuasive only when an observed signal can be tied to a physically defensible explanation. Compact objects such as neutron stars and black holes are natural laboratories for extreme physics, but the distance and complexity of these systems make interpretation difficult without multi-wavelength coverage and careful modeling. A detection without a mechanism is only half a result. the other half comes from showing that the signal fits quantitatively inside a coherent physical picture rather than merely being consistent with a broad family of models. Struggled to find them, and it took more than a decade to find the first 10 of them at z≥7. Euclid is a wide-angle telescope with a 600 megapixel camera.

Not only that, it will observe more than 200, 000 high-redshift galaxies with near-infrared photometry and spectroscopy. This is almost the perfect setup for finding luminous quasars during the Epoch of Reionization (EOR), which spans from z=6 to z=9.

As a result, Euclid has now found 31 new quasars at 6.6 < z < 7.8. These two were shining with the light of trillions of Suns only 670 million years after the Big Bang, when the Universe was only about 5% of its current age.

Since 12 of the new quasars are at z ≥ 7, this more than doubles the number of quasars discovered at that redshift, which corresponds to the Universe's first 770 million years. But with these 31 new high-redshift quasars, scientists have more of a representative sample to work with.

The broader interest lies in turning an observational clue into something that can be weighed against competing models of the underlying physics. Astrophysics does not have the luxury of controlled experiments; everything is inferred from radiation that traveled across cosmic distances under conditions that cannot be reproduced in a terrestrial laboratory. This makes the interpretation chain longer and more uncertain than in bench science, but it also means that a well-constrained measurement of an extreme object carries theoretical information that no earthbound experiment can provide.

The Euclid team has taken a true ‘census’ of quasars at the dawn of the Universe for the first time. They're interesting in themselves, but also time machines that enable us to explore the early Universe and understand how the first generation of galaxies came to be,” says ESA.

Because this item comes through Universe Today as science journalism, it should be treated as contextual reporting rather than primary evidence. Good science reporting can identify why a result matters, connect it to the wider literature and make technical work readable, but the decisive evidence remains in the original paper, dataset, mission release or technical record. That distinction is especially important when a story is later repeated by aggregators, because repetition increases visibility, not evidential strength.

The next step is to see whether independent datasets and physical modeling converge on the same interpretation. Multi-wavelength follow-up, combining X-ray, radio and optical data where possible, is typically what separates a compelling detection from a robust physical characterization. In high-energy astrophysics, results that initially looked definitive have been revised when data from a second messenger arrived; the current result should be read with that history in mind.

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