The European Space Agency’s Euclid telescope has identified 31 quasars from the epoch of reionization, doubling the known population of these ancient beacons. The two oldest, whose light travelled for over 13 billion years, date to when the universe was just 670 million years old—20 million years earlier than the previous record-holder. This pushes direct observation closer to the cosmic dark ages and immediately sharpens a long-standing astrophysical quandary: the supermassive black holes powering these quasars appear far too massive to have assembled in so short a time.

Quasars are the intensely luminous cores of early galaxies, fuelled by black holes accreting matter at extreme rates. Because their brilliance can outshine entire galaxies, they serve as backlights to probe the intervening gas, allowing astronomers to trace the reionization process that ended the universe’s opaque infancy. The new Euclid sample, drawn from a wide-area sky survey, provides a statistically significant set to study this era. Yet each additional early quasar reinforces the tension: objects weighing billions of solar masses already existed when the cosmos was less than 5% of its current age, challenging models of black hole formation and growth.

The Euclid results, published in Astronomy & Astrophysics by an international team led by Leiden University, come amid a broader observational push. The James Webb Space Telescope has produced the most detailed images yet of Centaurus A, a nearby active galaxy whose dust-obscured centre and warped structures reveal a history of mergers and episodic star formation—a form of “galactic archaeology” that complements the distant quasar studies. Meanwhile, the COSMOS-Web survey, also using Webb, has released the deepest wide-field map of the universe, tracing the cosmic web of filaments and voids and showing how dense environments first accelerated, then quenched, galaxy growth. Even the veteran Hubble telescope continues to contribute, resolving two distinct stellar populations in the 13-billion-year-old globular cluster NGC 6426, a relic from the Milky Way’s formation.

The Euclid team will now train Webb’s spectrographs on the newly discovered quasars to dissect their light and measure the mass of their central black holes, as well as the properties of surrounding gas. A parallel effort aims to detect quasars from even earlier times, around 630 million years after the Big Bang. The combined data from these observatories, researchers say, will assemble a chronicle of the first billion years, testing whether new physics or exotic seeding mechanisms are required to explain the precocious growth of cosmic structure.