Euclid Telescope Discovers 31 Ancient Quasars, Challenging Cosmic Early Growth

Europe's Euclid space telescope has made a groundbreaking discovery, identifying 31 of the oldest known quasars in a single survey. This significant find, announced on July 6, 2026, effectively doubles the known count of these ancient celestial objects from the universe's infancy. Quasars, characterized by their intensely bright galactic cores powered by supermassive black holes, offer a unique window into the early cosmos. The research detailing this discovery was published in the journal Astronomy & Astrophysics.

Antonio La Marca, a research fellow with the European Space Agency (ESA) involved in the Euclid mission, stated that the result "more than doubles the number of quasars we know of that are so ancient." He emphasized that this represents the first true survey of these objects, allowing astronomers to take a "true ‘census’ of quasars at the dawn of the Universe for the first time." Historically, astronomers have painstakingly located a small number of the most ancient quasars over more than a decade. Euclid, however, has achieved a similar feat in approximately one year of operation. The distance and age of these objects are measured by redshift, with higher numbers indicating greater distance and earlier cosmic times.

Among the 31 newly identified quasars, 12 exhibit redshifts of 7 or higher, placing them within the universe's first 770 million years. Two objects, however, stand out with record-breaking redshifts of 7.77 and 7.69, surpassing the previous record-holder's redshift of 7.64 from 2021. These two record-breakers radiated with the equivalent light of a trillion suns when the universe was only about 670 million years old, a mere 5 percent of its current estimated age of 13.8 billion years. The light detected by Euclid began its journey over 13 billion years ago.

Early Cosmic Mysteries Deepen

The immense power of these quasars is generated by supermassive black holes at their centers, each estimated to be a billion times the mass of our Sun. This rapid development presents a significant puzzle for astrophysicists, as the early universe had a relatively short time to allow such massive structures to form. "We don’t yet have a good understanding of how they grew so massive, so fast," noted study co-author Joseph Hennawi, referring to these objects as "monsters" that "somehow already existed when the universe was in its infancy." Every new discovery of such ancient, massive quasars intensifies this enigma. Daming Yang, the lead author of the study, explained that observing these systems, which "date back to the Universe’s infancy," helps researchers "understand how these enormous systems formed and grew so quickly," a question described as "one of the greatest mysteries in astrophysics."

Interestingly, Euclid was not specifically designed for such discoveries. Its primary mission involves mapping the distribution of dark matter and dark energy across a significant portion of the sky. The telescope was launched in July 2023 and commenced its scientific operations in February 2024. Yang highlighted the mission's unexpected capability, stating, "Before, we could only find a handful of the very brightest ancient quasars, but Euclid lets us search far more efficiently across huge areas of sky to capture much fainter light." This capability allows astronomers to efficiently search for these elusive objects, which are inherently rare in observational data, akin to finding "the ultimate ‘needle in a haystack’ problem," as described by Daniel Mortlock, a professor of astrophysics and statistics at Imperial College London.