James Webb Telescope Detects Frozen Water In Young Star System For The First Time

NDTV

03-06-2025

For decades, scientists have been fascinated by the mystery of how life originated on Earth and where our water came from. One long-standing theory suggests that water was present around our star, particularly in the outer reaches of the solar system in its early days. Recently, NASA researchers using the James Webb Space Telescope made a groundbreaking discovery that lends credence to this theory. They've found water ice in the debris disk that orbits HD 181327, a Sun-like star 155 light-years from Earth.
According to Science Alert, the star system, just 23 million years old, is significantly younger than our 4.6-billion-year-old Solar System. This youthful system is still in its formative stages, with a protoplanetary disk surrounding the star that hasn't yet coalesced into planets.
Chen Xie, an assistant research scientist at JHU and the study's lead author, said in a recent NASA press release, "Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn's rings and icy bodies in our Solar System's Kuiper Belt. The presence of water ice helps facilitate planet formation. Icy materials may also ultimately be 'delivered' to terrestrial planets that may form over a couple of hundred million years in systems like this."
Using the James Webb Space Telescope's near-infrared spectrograph (NIRSpec), researchers detected water ice in the debris disk surrounding HD 181327. The water ice was predominantly found in the outer debris ring, making up over 20% of its mass, in the form of "dirty snowballs", a combination of ice and fine dust particles.
The amount of water ice decreased closer to the star, with only 8% of the material consisting of ice halfway in from the disk's edge, and virtually none near the centre. This decrease is likely due to vaporisation from the star's ultraviolet radiation or potentially locked up in rocks and planetesimals.
"When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but before Webb, we didn't have instruments sensitive enough to make these observations. 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," said Christine Chen, an associate astronomer at the Space Telescope Science Institute (STScI) and co-author on the study.
Analysing these actively forming planetary systems will enhance our understanding of planet formation models and provide fresh insights into the origins of our own Solar System.