Europe's Euclid space telescope has spotted the oldest quasars ever observed, shining from a time when the universe was only 700 million years old. That is roughly 5 percent of its current age. The discovery pushes the known boundaries of how early these brilliant galactic cores existed.
A telescope built for dark energy finds ancient light
Euclid launched in July 2023 from Cape Canaveral, Florida, on a SpaceX Falcon 9 rocket. The European Space Agency built it primarily to map the geometry of the dark universe and study dark energy and dark matter. But during its early calibration phase, while testing its instruments, Euclid captured images of two extremely distant quasars. One of them, designated QSO J0843+0449, sits at a redshift of 7.04. The other, QSO J1554+1937, has a redshift of 7.07. Redshift measures how much the universe has stretched the light from an object. Higher numbers mean greater distance and earlier time. These are the highest redshift quasars ever confirmed by any telescope.
How scientists confirmed what Euclid saw
A team led by researchers from the University of Helsinki in Finland analyzed the data. They used follow up observations from the Very Large Telescope in Chile and the Keck Observatory in Hawaii to verify the objects. Quasars are supermassive black holes at the centers of galaxies that pull in gas and dust, heating them to extreme temperatures and releasing enormous amounts of energy. The light from these two quasars traveled for more than 13 billion years to reach Euclid's detectors. Finding them so early in the universe's history helps astronomers understand how black holes grew so large so quickly after the Big Bang.
Why this matters for understanding the early cosmos
For astronomers in Europe and around the world, these quasars are not just old. They are signposts. They show that supermassive black holes were already forming and feeding less than a billion years after the universe began. The discovery also proves that Euclid, despite being designed for a different mission, can find rare and distant objects during its survey. The telescope is expected to map billions of galaxies over six years. If it can spot quasars this far away during testing, its full survey could reveal many more. The findings were published in the journal Astronomy and Astrophysics.
Euclid's primary job is still to chart the large scale structure of the cosmos and measure the influence of dark energy. But this early result shows that a telescope built for one purpose can also uncover unexpected pieces of the universe's earliest history. The quasars are a reminder that the most distant light often holds the oldest stories.
