Astronomers using the James Webb Space Telescope (JWST) have detected water vapor within the debris disk surrounding HD 181327, a young, sun-like star located 155 light-years away. This discovery, published in Nature in 2024, provides valuable insights into how water, a crucial element for life, is delivered to forming planetary systems.
HD 181327, situated in the Telescopium constellation, is approximately 23 million years old, significantly younger than our Sun. The star is encircled by a wide ring of icy debris, the building blocks of comets. Collisions between these icy bodies release tiny grains of water ice mixed with dust.
JWST data indicates that the majority of water ice is concentrated in the outer, colder regions of the ring. This suggests that temperature variations prevent water from persisting in the inner regions closer to the star. According to scientist Christine Chen, these "snow lines," where ice forms from water vapor and other volatile substances, can significantly influence how water is transported to nascent rocky planets. The HD 181327 system is thought to resemble the early Kuiper Belt in our solar system, a region shaped by planets and filled with icy debris.