Free Astronomy Magazine July-August 2025

46 ASTRO PUBLISHING Spitzer Space Telescope hinted at the possibility of frozen water in this system. “Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in lo- cations like Saturn’s rings and icy bodies in our solar system’s Kuiper Belt,” said Chen Xie, the lead author of the new paper and an assistant research scientist at Johns Hopkins University in Baltimore, Maryland. All the frozen water Webb detected is paired with fine dust particles throughout the disk — like itsy-bitsy “dirty snowballs.” Astronomers have been waiting for this definitive data for decades. “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 in- struments sensitive enough to make these observations,” said Christine Chen, a co-author and an as- tronomer at the Space Telescope Sci- ence Institute in Baltimore. “What’s most striking is that this data looks similar to the telescope’s other re- cent observations of Kuiper Belt ob- jects in our own solar system.” Water ice is a vital ingredient in disks around young stars — it heav- ily influences the formation of giant planets and may also be delivered by small bodies like comets and as- teroids to fully formed rocky plan- ets. Now that researchers have JULY-AUGUST 2025 I s frozen water scattered in sys- tems around other stars? As- tronomers have long expected it is, partially based on previous detec- tions of its gaseous form, water vapor, and its presence in our own solar system. Now there is definitive evidence: Researchers confirmed the presence of crystalline water ice in a dusty de- bris disk that orbits a Sun-like star 155 light-years away using detailed data known as spectra from NASA’s James Webb Space Telescope. (The term water ice specifies its makeup, since many other frozen molecules are also observed in space, such as carbon dioxide ice, or “dry ice.”) In 2008, data from NASA’s retired by NASA/ESA/CSA Christine Pulliam Webb identifies frozen water in young star system