NASA's James Webb Space Telescope has made the first-ever and long-anticipated detection of ice outside of our own solar system.
The frozen water was found within a debris disk circling HD 181327, a young, sun-like star that lies some 155 light-years from Earth in the constellation of Telescopium.
The ice is paired up with fine dust particles in the disk— forming what has been dubbed "itsy-bitsy dirty snowballs"—with more further out from the star, where it is colder.
Astronomers refer to what we would call ice as "water ice," to distinguish it from other frozen molecules such as, for example, carbon dioxide in the form of "dry ice."
"Webb unambiguously detected not just water ice, but crystalline water ice," said paper author and astronomer Chen Xie of Johns Hopkins University in Baltimore.
Crystalline water ice, Xie explained, is known to be found in various places within our solar systems—from some of the moons of the outer planets to Saturn's rings, comets and other rocks that make up the Kuiper Belt at the edge of the solar system.
Astronomers have been waiting for such a definitive detection of water ice elsewhere in the universe for decades, based on the previous detections of water vapor out among the stars, as well as where frozen water ice can be found in our own solar system.
"When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn't have instruments sensitive enough to make these observations," explained paper author and astronomer Christine Chen of the Space Telescope Science Institute, also in Baltimore, in a statement.
Webb confirmed the presence of water ice around HD 181327 after hints of such were revealed by NASA's Spitzer Space Telescope back in 2008.
Chen added: "What's most striking is that this data looks similar to the telescope's other recent observations of Kuiper Belt objects in our own solar system."
In fact, the team said, billions of years ago our Kuiper Belt was likely very similar to the debris disk around HD 181327, when our solar system was similarly young.
"HD 181327 is a very active system. There are regular, ongoing collisions in its debris disk," said Chen.
"When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect."
With this study complete, the researchers will continue to search for other examples of water ice in debris disks and actively forming planetary systems across the Milky Way.
"The presence of water ice helps facilitate planet formation," Xie noted.
"Icy material may also ultimately be 'delivered' to terrestrial planets that may form over a couple hundred million years in systems like this."
The detection of water ice elsewhere in the galaxy, thus, should well pave the way for scientists to study how these processes play out in other planetary systems.
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Reference
Xie, C., Chen, C. H., Lisse, C. M., Hines, D. C., Beck, T., Betti, S. K., Pinilla-Alonso, N., Ingebretsen, C., Worthen, K., Gáspár, A., Wolff, S. G., Bolin, B. T., Pueyo, L., Perrin, M. D., Stansberry, J. A., & Leisenring, J. M. (2025). Water ice in the debris disk around HD 181327. Nature, 641(8063), 608–611. https://doi.org/10.1038/s41586-025-08920-4