Free Astronomy Magazine July-August 2026 ARABIC VERSION

high water content — water that carries frozen chemical records of the environment in which they formed.Alongsideordinarywater (H ₂ O), comets contain a molecular variantcalleddeuteratedwater (HDO),inwhichonehydrogenatom is replaced by deuterium, a hydro- genatomwithanextraneutron.In Solar System comets, roughly one molecule of semi-heavy water exists foreverytenthousandmoleculesof ordinary water. In 3I/ATLAS, that ratio is at least 30 times higher — and over 40 times the proportion found in Earth’s oceans. Notably,ordinarywater(H ₂ O) itselffellbelowALMA’s detection threshold dur- ing these observations. The team con- strainedtheD/Hratio indirectly, by detectingHDOdirectly and in- ferring the water produc- tion rate throughthe excitationofm e t h a n o l lines—aso- phi sticated modelingap- proach that showcases ALMA’sunique analyticalcapa- bilities. This elevated ratio points to an origin in anexceptionallycold andchemicallydistinct environment. “The chemical processes that lead to the en- hancementofdeuteratedwaterare really sensitive to temperature andusuallyrequireenvironments colderthanabout30Kelvin,oraboutmi nus406degreesFahren- heit,” explained Salazar Manzano. Theratiowassetasthecomet’s home system formed and has been preserved intact throughout its in- terstellar journey. ALMA’s instrumental role in this dis- covery was essential. Paneque-Car- reño noted: “Most instruments can’t point toward the Sun, but radio tel- escopes like ALMA can. We wereable to observe the comet within days after perihelion, just as it peeked out from its transit behind theSun.Thisgaveusaconstrainton these molecules that’s not possible using other instruments.” Beyondbeingachemicalfingerprint of a distant planetary system, the HDO/H ₂ Oratiocarriesaspecialcos- mological significance: the abun- dancesofdeuteriumandhydrogen were set during the Big Bang it- self, making this measurement a uniquelyfundamentalprobeof the conditions under which other worlds are born. “Each interstellar cometbringsalittlebitofitshistory, itsfossils,fromelsewhere.Wedon’t knowexactlywhere,butwithinstru- ments like ALMA we can begin to understand the conditions of that place and compare them to our own,” saidPaneque-Carreño.     JULY-AUGUST2026 ﺗﺤﺘﻮي ا ﺬﻧﺒﺎ ت ﻋﲆ ﻧﻮع ﺟﺰﻳﺌﻲ ﻳُﻌﺮف ﺑﺎﺳ ﻢ ا ﺎء ا ُﺜﻘﱠ ﻞ ﺑﺎﻟﺪﻳﻮﺗ ﻳﻮم ﺣﻴﺚ ﻳ ﺴـﺘﺒﺪل أﺣـﺪ ذرﺗﻲ اﻟﻬﻴﺪروﺟ ﺑﺬرة دﻳﻮﺗ ﻳﻮم وﻫﻲ ﻧﻈ ﻟﻠﻬﻴﺪروﺟ ﻳﺤﺘﻮي ﻋﲆ ﻧﻴﻮﺗﺮون إﺿـﺎﰲ ﰲ . ﻣﺬﻧﺒﺎت اﻟﻨﻈﺎم اﻟﺸﻤﴘ، ﻳﻮﺟﺪ ﺗﻘﺮﻳﺒﺎً ﺟﺰيء واﺣﺪ ﻣﻦ ا ﺎء ﺷﺒﻪ اﻟﺜﻘﻴﻞ ﻣﻘﺎﺑﻞ ﻛﻞ ﻋﴩـة آﻻف ﺟﺰيء ﻣﻦ ا ﺎء اﻟﻌـﺎدي . أﻣـﺎ ﰲ ا ـﺬﻧﺐ 3I/ATLAS ﻓﺈن ﻫﺬه اﻟﻨﺴﺒﺔ أﻋﲆ ﺑﻤﺎ ﻻ ﻳﻘﻞ ﻋﻦ 30 ﻣﺮة وأﻛﱪ ﺑـﺄﻛﺜﺮ ﻣـﻦ 40 ﻣـﺮة ﻣـﻦ اﻟﻨﺴﺒﺔ ا ﻮﺟـﻮدة ﰲ ﻣﺤﻴﻄـﺎت اﻷرض وﻣـﻦ اﻟﻼﻓﺖ أن ا ﺎء اﻟﻌﺎدي ﻧﻔﺴﻪ ﻛﺎن أﻗﻞ ﻣﻦ ﺣﺪ اﻟﻜﺸﻒ اﻟﺬي ﻳﺴﺘﻄﻴﻊ ﻣﺮﺻﺪ أ ﺎ رﺻﺪه أﺛﻨﺎء ﻫﺬه اﻷرﺻﺎد وﻗﺪ ﺗﻤﻜﻦ اﻟ ـ ﻔﺮﻳﻖ ﻣﻦ ﺗﻘﻴـ ﻴﺪ ـ ـﻧ ﺴﺒﺔ اﻟﺪﻳﻮ ﺗ ﻳﻮم إﱃ اﻟ ﻬﻴﺪروﺟ ـ ﺑﺼﻮرة ﻏ ﻣﺒﺎﴍة وذﻟﻚ ـ ﻣﻦ ﺧ ﻼل اﻟﻜﺸﻒ ا ﺒﺎﴍﻋﻦ ﺟﺰﻳﺌﺎت ا ﺎء ا ﺜ ﻘﻞ ــ ﺑﺎﻟﺪﻳﻮﺗ ﻳﻮم واﺳﺘﻨﺘﺎج ﻣﻌ ﺪل ـ إﻧﺘﺎج ا ﺎء ﻣﻦ ﺧﻼل دراﺳﺔ ﻣﻦ ﺣﺎﻻت إﺛﺎرة ﺧﻄﻮط ﻴﺔـﻄﻴﻔ ـ ﻮل اﻟ ـ ﻴﺜﺎﻧ ـا وﻫﻮ أﺳﻠﻮب ﻧﻤﺬﺟﺔ ﺘﻘﺪم ﻳ ـﻣ ﺮ ـﻈﻬ ــ اﻟﻘﺪرات اﻟﺘﺤﻠﻴﻠﻴﺔ ﺪـﻔﺮﻳ ـاﻟ ة ﺮﺻﺪ ا ﺎ وﺗﺸ اﻟﻨﺴﺒﺔ ا ﺮﺗ ـ ﻔﻌﺔ إﱃ أن أﺻﻞ ا ﺬﻧﺐ ﻫﺬا ـ ﻌﻮد إﻟ ـﻳ ﻰ ﺑﻴﺌﺔ ـﺷ ﺪﻳﺪة اﻟﺒ ﺮودة ـ وﻣﺘﻤﻴﺰة ﻛﻴﻤﻴﺎﺋﻴﺎً . ﺎﻻزار ـﺢ ﺳـ وأوﺿ ﻨﺰاﻧﻮ ﻗ ـﻣ إن »: ﻼً ـﺎﺋـ اﻟﻌﻤﻠﻴﺎت اﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻠﺘﻲ ﺗ ـا ﺆديـ ﺑﺎﻟﻔـﻌﻞ إﱃ ﺎدة ﻧ ـزﻳ ﺎء ا ُﺜ ـ ﺴﺒﺔ ا ـ ﻘﱠ ﻞـ ﺑﺎﻟﺪﻳﻮﺗ ﻳﻮم ﻋـﺎﱄ اﻟﺤﺴ ﺎﺳﻴﺔ ﻟﺪرﺟﺔ اﻟ ـ ﺤﺮارة وﻋﺎدة ﺎ ـﻣ ﺗﺘﻄﻠﺐ ـﺑﻴ ﺌﺎت أﺑﺮد ﻣﻦ ﻧﺤﻮ 30 ﻠﻔﻦـﻛ أي ﻣﺎ ﻳﻌﺎدل ﺣﻮاﱄ 406 درﺟﺎت ﻓﻬﺮﻧﻬﺎﻳـﺖ ﺗﺤـﺖ اﻟﺼﻔﺮ . « وﻗﺪ ﺗﺤـﺪدت ﻫـﺬه اﻟﻨﺴـﺒﺔ أﺛﻨـﺎء ﺗﺸﻜّﻞ اﻟﻨﻈﺎم اﻟﻨﺠﻤﻲ اﻷﺻﲇ ﻟﻠﻤﺬﻧﺐ، وﻇﻠﺖ ﻣﺤﻔﻮﻇـﺔ دون ﺗﻐﻴـ ﻃـﻮال رﺣﻠﺘـﻪ ﻋـﱪ اﻟﻔﻀﺎء ﺑ اﻟﻨﺠﻤﻲ . وﻛﺎن اﻟﺪور اﻟﺬي ﻟﻌﺒـﻪ ﺮﺻﺪ ﻣ أ ﺎ اﻟﻔﻠﻜﻲ ﰲ ﻫﺬا اﻻﻛﺘﺸﺎف أﺳﺎﺳﻴﺎً . وﻗﺎﻟﺖ ﺑﺎﻧﻴﻜﻲ »: ﻛﺎرﻳﻨﻴﻮ - ﻻ ﺗﺴﺘﻄﻴﻊ ﻣﻌﻈﻢ ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 5 وﻗﺎﻟﺖ ﺑﺎﻧﻴﻜﻲ ﺎرﻳﻨﻴﻮ ﻛ ﺴﻳﻻ »: ﺘﻄﻴﻊ ﻣﻌﻈـﻢ اﻷﺟﻬﺰة اﻟﺮﺻﺪﻳﺔ اﻟﺘﻮﺟﻪ ﻧﺤﻮ اﻟﺸﻤﺲ ﻟﻜـﻦ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﺮادﻳﻮﻳﺔ ﻣﺜﻞ ﻣﺮﺻﺪ أ ﺎ اﻟﻔﻠﻜﻲ ﺗﺴﺘﻄﻴﻊ ذﻟﻚ . ﻟﻘﺪ ﺗﻤﻜﻨﺎ ﻣﻦ رﺻﺪ ا ﺬﻧﺐ ﺧﻼل أﻳـﺎم ﻗﻠﻴﻠـﺔ ﻓﻘﻂ ﺑﻌﺪ اﻟﺤﻀﻴﺾ اﻟﺸﻤﴘ ﻓـﻮر ﺧﺮوﺟـﻪ ﻣﻦ ﻣﺮوره ﺧﻠﻒ اﻟﺸﻤﺲ وﻗﺪ أﺗﺎح ﻟﻨـﺎ ذﻟـﻚ وﺿﻊ ﻗﻴﻮد ﻋﲆ وﺟﻮد ﻫﺬه اﻟﺠﺰﻳﺌﺎت ﺑﻄﺮﻳﻘﺔ ﻻ ﻳﻤﻜﻦ ﺗﺤﻘﻴﻘﻬﺎ ﺑﺎﺳﺘﺨﺪام أدوات أﺧـﺮى . « وإﱃ ﺟﺎﻧﺐ ﻛﻮﻧﻬﺎ ﺑﺼـﻤﺔ ﻛﻴﻤﻴﺎﺋﻴـﺔ ﻟﻨﻈـﺎم ﻛﻮﻛﺒﻲ ﺑﻌﻴﺪ ﺗﺤﻤﻞ ﻧﺴﺒﺔ ا ﺎء اﻟﻌﺎدي / ا ـﺎء ا ﺜﻘﻞ ﺑﺎﻟﺪﻳﻮﺗ ﻳﻮم أﻫﻤﻴﺔ ﻛﻮﻧﻴـﺔ ﺧﺎﺻـﺔ إذ إن وﻓﺮة اﻟﺪﻳﻮﺗ ﻳﻮم واﻟﻬﻴﺪروﺟ ﻗﺪ ﺗﺤﺪدت ﻣﻨﺬ اﻻﻧﻔﺠﺎر اﻟﻌﻈﻴﻢ ﻧﻔﺴﻪ ﻣﻤﺎ ﻳﺠﻌﻞ ﻫـﺬا اﻟﻘﻴــﺎس أداة أﺳﺎ ﺳــﻴﺔ وﻓﺮﻳــﺪة ﻟﺪراﺳــﺔ اﻟﻈﺮوف اﻟﺘﻲ ﺗﻮﻟﺪ ﻓﻴﻬﺎ اﻟﻌﻮاﻟﻢ اﻷﺧﺮى . أﺿﺎﻓﺖ ﺑﺎﻧﻴﻜﻲ »: ﻛﺎرﻳﻨﻴﻮ ﻳﺠﻠﺐ ﻛـﻞ ﻣـﺬ ﻧﺐ ﺑ ﻧﺠﻤﻲ ﻣﻌﻪ ﺟﺰءاً ﻣﻦ ﺗﺎرﻳﺨﻪ وأﺣﻔﻮراﺗﻪ اﻟﻘﺎدﻣﺔ ﻣﻦ ﻣﻜﺎن آﺧﺮ ﻓﻬﻮ ﻳﺤـﺘﻔﻆ داﺧـﻞ ﺟﻠﻴﺪه وﺗﺮﻛﻴﺒﻪ اﻟﻜﻴﻤﻴﺎﺋﻲ ﺑﺴـﺠﻞٍ ﻣﺤﻔـﻮظ ﻣﻨﺬ ﻣﺮاﺣﻞ ﻣ ﺒﻜﺮة ﺟﺪاً ﻣـﻦ ﺗﺸـﻜ ﻞ ﻧﻈﺎﻣـﻪ اﻟﻨﺠﻤﻲ در ﻴﺢ ﻣﻤﺎ ﻳﺘ اﺳﺔ ﺑﻴﺌـﺎت ﻛﻮﻧﻴـﺔ ﻟـﻢ ﻳﻜﻦ اﻟﻮﺻﻮل إﻟﻴﻬﺎ ﻣﻤﻜﻨﺎً ﺑﺸﻜﻞ ﻣﺒﺎﴍ . ﻧﺤﻦ ﻻ ﻧﻌﺮف ﻋﲆ وﺟﻪ اﻟﺪﻗﺔ ﻣﻦ أﻳـﻦ ﺟـﺎء ﻟﻜﻦ ﺑﻔﻀﻞ أدوات ﻣﺜﻞ ﻣﺮﺻـﺪ أ ـﺎ اﻟﻔﻠﻜـﻲ ﻳﻤﻜﻨﻨﺎ أن ﻧﺒـﺪأ ﺑﻔﻬـﻢ ﻇـﺮوف ذﻟـﻚ ا ﻜـﺎن وﻣﻘﺎرﻧﺘﻬﺎ ﺑﻈﺮوف ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ . - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 6