Space
Euclid Just Found 31 Ancient Quasars — Including the Most Distant One Ever Seen
The Euclid space telescope has uncovered 31 new quasars shining from the universe's first roughly 800 million years — a haul that includes the most distant quasar ever confirmed. Because light from these objects has traveled for over 13 billion years, they are effectively snapshots of cosmic infancy, when the first galaxies were still assembling.
A quasar is not a star but a galaxy's violent core: a supermassive black hole devouring surrounding gas, heating it into a beacon brighter than entire galaxies combined. The farther away one is, the earlier in cosmic history we see it. Euclid's most distant new find sits at a redshift of about 7.8, meaning the universe was only about 5% of its current age when that light began its journey.
Why Euclid changes the game
Depth plus sky coverage. Euclid was built to map the dark universe across enormous swaths of sky with unusual sensitivity. That combination — wide and deep at once — is exactly what quasar hunting needs. Traditional surveys either covered huge areas too shallowly or stared deeply at tiny patches, missing the rare brightest objects of the early universe. Euclid's wide survey, barely a year and a half in, is already flipping that trade-off.
Reaching the faint end of the luminosity function. The new quasars span a range of brightness that extends quasar studies down to their faint population, the ones too dim for earlier instruments. Finding 31 at once — rather than one celebrated object at a time — lets astronomers study early black holes as a population, not as anecdotes.
What the discoveries tell us
Black holes grew fast, and we don't fully know how. Seeing massive, feeding black holes so early forces a puzzle: how did they accumulate so much mass when the universe was still a toddler? Competing ideas — seeds from the first stars versus direct collapse of giant gas clouds — both strain under the observed masses. A larger sample sharpens that test.
A new map of the early cosmos. Each quasar also acts as a backlight, illuminating the gas between us and it. Studied together, the 31 new sources become probes of how matter was distributed when the first galaxies lit up, helping chart the universe's transition out of its dark ages.
The survey is just getting started. Euclid is planned to scan about one-third of the sky over six years. If the first stretch already yielded 31 ancient quasars, the full survey could multiply that count and possibly push the distance record even further back toward the cosmic dawn.