James Webb Solves Mystery of Strange Red Dots in Space

For years, tiny red dots scattered across James Webb Space Telescope images puzzled astronomers who couldn't explain what they were seeing in the early universe.

Scientists at the University of Copenhagen just solved the mystery. These glowing red objects are young black holes wrapped in thick cocoons of gas, feasting on their surroundings and growing at incredible speed.

The discovery answers a question that's bothered astronomers since December 2021, when Webb first sent back images from its position 1.5 million kilometers from Earth. The strange dots appeared during a time when the universe was only a few hundred million years old, then vanished about a billion years later.

At first, researchers thought the dots might be massive galaxies. That didn't make sense because galaxies that large shouldn't exist so soon after the Big Bang. After two years of analyzing Webb's data, the team at the Niels Bohr Institute's Cosmic Dawn Centre found the real answer.

"The little red dots are young black holes, a hundred times less massive than previously believed, enshrouded in a cocoon of gas, which they are consuming in order to grow larger," says Professor Darach Watson, who led the study published in Nature. The gas generates enormous heat as it spirals toward the black hole, and that radiation shining through the cocoon creates the signature red glow.

These baby black holes weigh up to 10 million times the mass of our Sun and stretch about 10 million kilometers across. They're messy eaters. Most of the gas they try to swallow gets blown back out from their poles as they spin, but the material that does fall in releases more energy than almost any other phenomenon in the universe.

Why This Inspires

This discovery fills in a missing chapter of cosmic history. Scientists have long wondered how supermassive black holes could exist just 700 million years after the Big Bang, some already weighing billions of times more than our Sun.

Now we're watching them grow up. The Webb telescope caught these black holes in the middle of their most intense growth spurt, a phase no one had observed before. Every large galaxy, including our Milky Way, has a supermassive black hole at its center that went through this same violent phase billions of years ago.

Understanding how the first black holes formed and grew helps explain how the universe evolved from its chaotic early days into the structured cosmos we see today. What looked like mysterious dots turned out to be windows into the universe's wild youth.

Scientists have now identified hundreds of these little red dots, each one a cosmic baby learning to eat.