Free Astronomy Magazine July-August 2025 ARABIC VERSION

Webb identifies frozen water in young star system byNASA/ESA/CSA ChristinePulliam s frozen water scattered in sys- temsaroundotherstars?As- tronomers have long expected itis,partiallybasedonpreviousdetec- tionsofitsgaseousform,water vapor,anditspresenceinourown solarsystem. Now there is definitive evidence: Researchers confirmed the presence ofcrystallinewatericeinadustyde- 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.”) In2008,datafromNASA’sretired Spitzer Space Telescope hinted at thepossibilityoffrozenwaterinthis system. “Webbunambiguouslydetected notjustwaterice,butcrystalline waterice,whichisalsofoundinlo- cationslikeSaturn’sringsandicy bodiesinoursolarsystem’sKuiper Belt,” saidChenXie,theleadauthor of the new paper and an assistant researchscientistatJohnsHopkins University in Baltimore, Maryland. AllthefrozenwaterWebbdetected ispairedwithfinedustparticles throughoutthedisk—likeitsy-bitsy “dirty snowballs.” Astronomers have been waiting for this definitive data fordecades. “WhenIwasagraduatestudent25 yearsago,myadvisortoldmethere shouldbeiceindebrisdisks,but prior to Webb, we didn’t have in- struments sensitive enough to make these observations,” said Christine Chen,aco-authorandanas- tronomerattheSpaceTelescopeSci- ence Institute in Baltimore. “What’s moststrikingisthatthisdatalooks similartothetelescope’sotherre- cent observations of Kuiper Belt ob- jects in our own solar system.” Watericeisavitalingredientin disks around young stars — it heav- ilyinfluencestheformationofgiant planets and may also be delivered bysmallbodieslikecometsandas- teroids to fully formed rocky plan- ets.Nowthatresearchershave JULY-AUGUST2025 I ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 46 ﻳﺮﺻﺪ و ﺐ ﺎً ﻣ ﺎﻫ ﻣﺘ ﻤﺪة ﻓﻲﻧﻈﺎم ﻧ ﻤﻲﺷﺎب : ﻘﻠﻢ ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ ﻫﻞ ﻳﻨﺘﴩ ا ﺎء ا ﺘﺠﻤﺪ ﰲ أﻧﻈﻤﺔ ﺣﻮل ﻧﺠﻮم أﺧﺮى ؟ ﻟﻄﺎ ﺎ ﺗﻮﻗـﻊ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ وﺟـﻮده وﻳﻌﺘﻤﺪ ذﻟﻚ ﺟﺰﺋﻴ ﺎً ﻋـﲆ اﻛﺘﺸـﺎﻓﺎت ﺳـﺎﺑﻘﺔ ﻟﺘﻮاﻓﻘـﻪ ﻣـﻊ ﺷـﻜﻠﻪ اﻟﻐـﺎزي وﺑﺨـﺎر ا ـﺎء ووﺟﻮده ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ اﻵن . ﻫﻨﺎك دﻟﻴﻞ ﻓﻘﺪ ﻗﺎﻃﻊ أﻛﺪ اﻟﺒﺎﺣﺜﻮن وﺟﻮد ﺟﻠﻴـﺪ ﻣـﺎﺋﻲ ﺑﻠﻮري ﰲ ﻗﺮص ﻣﻦ ﺣﻄﺎم اﻟﻐﺒﺎر ﻳﺪور ﺣﻮل ﻧﺠﻢ ﺷﺒﻴﻪ ﺑﺎﻟﺸﻤﺲ ﻳﺒﻌﺪ 155 ﺳﻨﺔ ﺿـﻮﺋﻴﺔ وذﻟـﻚ ﺑﺎﺳـﺘﺨﺪام ﺑﻴﺎﻧـﺎت ﻣﻔﺼـﻠﺔ ﺗ ﻌـﺮف ﺑﺎﻷﻃﻴــﺎف ﻣ ـﻦ ﺗﻠﺴ ـﻜﻮب ﺟ ـﻴﻤﺲ وﻳ ـﺐ اﻟﻔﻀــﺎﺋﻲ اﻟﺘ ـﺎﺑﻊ ﻟ ﻮﻛﺎﻟــﺔ ﻧﺎﺳ ـﺎ . ) ﻳﺤــﺪد ﻣﺼﻄﻠﺢ ﺟﻠﻴﺪ ا ﺎء ﺗﺮﻛﻴﺒﻪ ﻧﻈﺮ اً ﻟﺮﺻﺪ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﺠ ﺰﻳﺌﺎت ا ﺘﺠﻤـﺪة اﻷﺧـﺮى ﰲ اﻟﻔﻀـﺎء ﻣﺜﻞ ﺟﻠﻴﺪ ﺛﺎﻧﻲ أﻛﺴﻴﺪ اﻟﻜﺮﺑـﻮن " أو اﻟﺠﻠﻴـﺪ اﻟﺠﺎف .(" ﰲ ﻋﺎم 2008 أﺷﺎرت ﺑﻴﺎﻧـﺎت ﻣـﻦ ﺗﻠﺴﻜﻮب ﺳﺒﻴﺘﺰر اﻟﻔﻀﺎﺋﻲ ا ُﺘﻘﺎﻋـﺪ اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ إﱃ اﺣﺘﻤ ﺎل وﺟﻮد ﻣﺎء ﻣﺘﺠﻤﺪ ﰲ ﻫﺬا اﻟﻨﻈﺎم . ﻗﺎل ﺗﺸﻦﳾ ا ﺆﻟـﻒ اﻟﺮﺋﻴـ ﴘ ـ ﻟﻠﻮرﻗﺔ اﻟﺒﺤﺜﻴﺔ اﻟﺠﺪﻳﺪة وﺑﺎﺣـﺚ ﻣﺴـﺎﻋﺪ ﰲ ﺟﺎﻣﻌﺔ ﺟـﻮﻧﺰ ﻫـﻮﺑﻜﻨﺰ ﰲ ﺑـﺎﻟﺘﻴﻤﻮر ﺑﻮﻻﻳـﺔ : " ﻣﺎرﻳﻼﻧﺪ ﻟﻢ ﻳﻜﺘﺸﻒ ﺗﻠﺴﻜﻮب وﻳﺐ ﺑﺸـﻜﻞٍ واﺿﺢ ﺟﻠﻴﺪ اً ﺎً ﻣﺎﺋﻴ ﻓﺤﺴﺐ ﺑﻞ ﺟﻠﻴـﺪ اً ﺎً ﻣﺎﺋﻴـ ﺎً ﺑﻠﻮرﻳ واﻟـﺬي ﻳﻮﺟـﺪ أﻳﻀـ ﺎً ﰲ ﻣﻮاﻗـﻊ ﻣﺜـﻞ ﺣﻠﻘﺎت زﺣﻞ واﻷﺟﺴـﺎم اﻟﺠﻠﻴﺪﻳـﺔ ﰲ ﺣـﺰام ﻛﺎﻳﱪ ﺑﻨﻈﺎﻣﻨﺎ اﻟﺸ ". ﻤﴘـ ﺟﻤﻴـﻊ ﺟﺰﻳﺌـﺎت ا ﺎء ا ﺘﺠﻤﺪ اﻟﺬي اﻛﺘﺸﻔﻬ ﺎ ﺗﻠﺴـﻜﻮب وﻳـﺐ ﻣﻘﱰن ﺑﺠﺴﻴﻤﺎت اﻟﻐﺒـ ﺎر اﻟﻨـﺎﻋﻢ ﰲ ﺟﻤﻴـﻊ أﻧﺤﺎء اﻟﻘﺮص " ﻣﺜـﻞ ﻛـﺮات اﻟـﺜﻠﺞ ا ﻐـﱪة " اﻟﺼﻐ . اً ة ﺟﺪ وﻗﺪ اﻧﺘﻈﺮ ﻋﻠﻤﺎء اﻟﻔﻠـﻚ ﻫـﺬه ا ﻟﺒﻴﺎﻧﺎت اﻟﺤﺎﺳﻤﺔ ﻟ . ﻌﻘـﻮد ﻗﺎﻟـﺖ ﻛﺮﻳﺴـﺘ ﺗﺸﻦ ا ﺆﻟﻔﺔ ا ﺸﺎرﻛﺔ وﻋﺎ ﺔ اﻟﻔﻠﻚ ﰲ ﻣﻌﻬـﺪ ﻋﻠﻮم ﺗﻠﺴﻜﻮب اﻟﻔﻀﺎء ﰲ ﺑﺎﻟﺘﻴﻤﻮر " : ﻋﻨـﺪﻣﺎ ــ ـــــــــــــــــــــــــــــــــــ ﻛﻨﺖ ﻃﺎﻟﺒـﺔ دراﺳـﺎت ﻋﻠﻴـﺎ ﻗﺒـﻞ 25 ﺎً ﻋﺎﻣـ أ ـ ﺧﱪﻧﻲ ﻣ ﴩﰲ أﻧﻪ ﻣﻦ ا ﻔﱰض وﺟﻮد ﺟﻠﻴﺪ ﰲ أﻗﺮاص اﻟﺤﻄﺎم وﻟﻜﻦ ﻗﺒﻞ ﺗﻠﺴﻜﻮب وﻳـﺐ ﻟﻢ ﺗﻜﻦ ﻟﺪﻳﻨﺎ أﺟﻬـﺰة ﺣ ﺴﺎﺳـﺔ ﺑﻤـﺎ ﻳﻜﻔـﻲ ﻹﺟﺮاء ﻫﺬ ا اﻟﺮﺻﺪ و اﻷﻣﺮ اﻷﻛﺜﺮ إﺛﺎرة ﻟﻠﺪﻫﺸﺔ ﻫﻮ أن ﻫ ﺬه اﻟﺒﻴﺎﻧﺎت ﺗﺒﺪو ﻣﺸـﺎﺑﻬﺔ ﻷرﺻـﺎد اﻟﺘﻠﺴﻜﻮب اﻷﺧ ة اﻷﺧﺮى ﻷﺟﺮام ﺣﺰام ﻛﺎﻳﱪ ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ . ﻳﻌﺪ ا ﻟﺠﻠﻴﺪ ا ﺎﺋﻲ ﻋﻨﴫاً ﺣﻴﻮﻳﺎً ﰲ اﻷﻗـﺮاص ا ﺤﻴﻄﺔ ﺑﺎﻟﻨﺠﻮم اﻟﺸﺎﺑﺔ ﻓﻬﻮ ﻳﺆﺛﺮ ﺑﺸﺪة ﻋﲆ ﺗﻜﻮﻳﻦ اﻟﻜﻮاﻛﺐ اﻟﻌﻤﻼﻗﺔ وا ﺬﻧﺒﺎت وﻳﺴـﻬﻢ ﰲ ﻧﺸﺄة اﻟﺤﻴﺎة وﻗﺪ ﺗﻨﺘﻘﻞ أﻳﻀﺎً ﻣﻦ أﺟﺴـﺎم ﺻﻐ ة ﻣﺜﻞ ا ﺬﻧﺒﺎت واﻟﻜﻮﻳﻜﺒﺎت إﱃ اﻟﻜﻮاﻛﺐ اﻟﺼﺨﺮﻳﺔ ا ﻜﺘﻤﻠﺔ اﻟﺘﻜﻮﻳﻦ . ﻣﻤﺎ ﻳﻮﻓﺮ ا ﻜﻮﻧﺎت اﻷﺳﺎﺳﻴﺔ ﻟﺒﻨـ ﺎء اﻟﻐـﻼف اﻟﺠﻮي وا ﺤﻴﻄﺎت ﻋﲆ اﻟﻜﻮاﻛﺐ اﻟﻨﺎﺷﺌﺔ . ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 5