In a far-off galaxy named Makani—Hawaiian for “wind”—astronomers have spotted something remarkable.
Tiny dust particles, heated by the light of newborn stars, were carried out of the galaxy by powerful winds triggered by a massive burst of star formation.
Over the course of 100 million years, this dust drifted farther and farther away until it reached the giant halo of gas that surrounds the galaxy, known as the circumgalactic medium, or CGM.
For the first time, scientists have directly detected the infrared glow of this distant dust, thanks to the powerful James Webb Space Telescope (JWST).
The discovery, published in The Astrophysical Journal on August 25, 2025, provides fresh insight into how dust and gas move in and out of galaxies, shaping their growth and evolution.
“Before this study, we didn’t have proof that dust could survive the long, harsh journey into the circumgalactic medium,” said University of Maryland astronomy professor Sylvain Veilleux, who led the project.
“Webb’s sensitivity made it possible to detect the dust clearly for the first time.”
Makani was chosen because it once went through a dramatic phase of starburst activity, producing a powerful galactic wind that expelled both gas and dust.
Previous studies, including one in 2019 led by physicist David Rupke, had confirmed that these winds carried large amounts of gas into the CGM. But what happened to the dust was still a mystery. Dust may be microscopic, but it is a key ingredient in the formation of stars, planets, and even the building blocks of life.
Webb revealed that while the dust degraded during its long trip, it did not fully disintegrate—even though it was surrounded by blisteringly hot gas, hotter than 10,000 Kelvin (about 17,000 degrees Fahrenheit).
Under such conditions, the dust should have been destroyed instantly. The researchers suggest that the particles may have been shielded by cooler clumps of gas that acted like protective cocoons, allowing them to survive.
The team now plans to take their study further by using Webb to capture a detailed spectrum, or “fingerprint,” of the dust. This will help them learn more about its exact properties, such as particle size and composition.
In the future, Veilleux hopes to investigate whether dust can travel even farther—beyond the halo of a galaxy into the intergalactic medium, the vast space between galaxies. If dust can survive a million light-years or more, it would suggest that these particles play a role in shaping not only galaxies themselves but the larger universe.
“Galaxies aren’t static,” Veilleux said. “They’re still evolving, and the constant flow of gas and dust in and out is part of what drives that change. With Webb, we’re finally starting to see this cycle in action.”
Source: University of Maryland.
