Free Astronomy Magazine July-August 2025 ARABIC VERSION

whose lower gravity allows the at- mospheric layers to expand, the tro- posphere extends up to about 27 miles (45 kilometers). Webb and Keck used different infrared filters to probe to different depths in Titan’s atmosphere, allowing as- tronomerstoestimatethealtitudes oftheclouds.Thescienceteamob- served clouds that appeared to movetohigheraltitudesoverape- riodofdays,althoughtheywerenot abletodirectlyseeanyprecipitation occurring. Titan is an object of high astrobio- logical interest due to its complex organic (carbon-containing) chem- istry. Organic molecules form the basisofalllifeonEarth,andstudy- ing them on a world like Titan may help scientists understand the pro- cesses that led to the origin of life on Earth. The basic ingredient that drives much of Titan’s chemistry is meth- ane, or CH 4 . Methane in Titan’s at- mosphere gets split apart by sun- lightorenergeticelectronsfromSat- urn’s magnetosphere, and then re- combines with other molecules to makesubstanceslikeethane(C 2 H 6 ) along with more complex carbon- bearing molecules. Webb’sdataprovidedakeymissing pieceforourunderstandingofthe chemicalprocesses:adefinitivede- tection of the methyl radical CH 3 . Thismolecule(called“radical”be- causeithasa“free”electronthatis notinachemicalbond)formswhen methaneisbrokenapart.Detecting thissubstancemeansthatscientists canseechemistryinactiononTitan for the first time, rather than just thestartingingredientsandtheend products. “For the first time we can see the chemicalcakewhileit’srisinginthe oven,insteadofjustthestartingin- gredients of flour and sugar, and then the final, iced cake,” said co- author Stefanie Milam of the God- dard Space Flight Center. This hydrocarbon chemistry has long-term implications for the fu- tureofTitan.Whenmethaneisbro- kenapartintheupperatmosphere, someofitrecombinestomakeother moleculesthateventuallyendupon Titan’s surface in one chemical form oranother,whilesomehydrogenes- capesfromtheatmosphere.Asare- sult, methane will be depleted over time, unless there is some source to replenish it. AsimilarprocessoccurredonMars, where water molecules were bro- ken up and the resulting hydrogen losttospace.Theresultwasthedry, desert planet we see today. “On Titan, methane is a consum- able.It’spossiblethatitisbeingcon- stantly resupplied and fizzing out of thecrustandinterioroverbillionsof years.Ifnot,eventuallyitwillallbe goneandTitanwillbecomeamostly airless world of dust and dunes,” said Nixon. MoreofTitan’smysterieswillbe probedbyNASA’sDragonflymis- sion,aroboticrotorcraftscheduled to land on Saturn’s moon in 2034. Making multiple flights, Dragonfly willexploreavarietyoflocations.Its in- depthinvestigationswillcomple- ment Webb’s global perspective. “Bycombiningalloftheseresources, includingWebb,NASA’sHubble SpaceTelescope,andground-based observatories,wemaintaincontinu- itybetweentheformerCassini/Huy- gens mission to Saturn and the up- coming Dragonfly mission,” added HeidiHammel,vicepresidentofthe AssociationofUniversitiesforRe- searchinAstronomyandaWebbIn- terdisciplinaryScientist.     JULY-AUGUST2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﻣﺮﺷﺤﺎت ﻣﺨﺘﻠﻔﺔ ﻟﻸﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء ﻟﺴﱪ أﻋﻤﺎ ق ﻣﺨﺘﻠﻔﺔ ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟﺘﻴﺘﺎن ﻣﻤﺎ ﺳﻤﺢ ﻟﻌﻠﻤﺎ ء اﻟﻔﻠﻚ ﺑﺘﻘـﺪﻳﺮ ارﺗﻔﺎﻋـﺎت اﻟﺴﺤﺐ وﻗﺪ ﻻﺣﻆ اﻟﻔﺮﻳﻖ اﻟﻌﻠﻤﻲ ﺳﺤﺒًﺎ ﺑﺪت وﻛﺄﻧﻬﺎ ﺗﺘﺤﺮك إﱃ ارﺗﻔﺎﻋﺎت أﻋﲆ ﻋـﲆ ﻣـﺪار ﻗﺮون ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ ﻋﺪم ﺗﻤﻜﻨﻬﻢ ﻣﻦ رؤﻳـﺔ أي ﻫﻄﻮل ﻳﺤﺪث ﺑﺸﻜﻞ ﻣﺒﺎﴍ . ﻳﻌﺪ ﺗﻴﺘﺎن ﺟﺴﻤ ﺎ ذا أﻫﻤﻴﺔ ﺑﻴﻮﻟﻮﺟﻴﺔ ﻓﻠﻜﻴـﺔ ﻋﺎﻟﻴﺔ ﻧﻈـﺮ اً ﻟﱰﻛﻴﺒـﻪ اﻟﻜﻴﻤﻴـﺎﺋﻲ اﻟﻌﻀـﻮي ا ﻌﻘﺪ ) ا ﺤﺘﻮي ﻋﲆ اﻟﻜﺮﺑﻮن .( ﺗ ﺸﻜﻞ اﻟﺠﺰﻳﺌﺎت اﻟﻌﻀﻮﻳﺔ أﺳﺎس اﻟﺤﻴﺎة ﻋﲆ اﻷرض وﻗﺪ ﺗﺴﺎﻋﺪ دراﺳﺘﻬﺎ ﻋﲆ ﻋـﺎﻟﻢ ﻣﺜـﻞ ﺗﻴﺘﺎن اﻟﻌﻠﻤﺎء ﻋﲆ ﻓﻬﻢ اﻟﻌﻤﻠﻴﺎت اﻟﺘﻲ أدت إﱃ ﻧﺸﺄة اﻟﺤﻴﺎة ﻋﲆ اﻷرض . إن ا ﻜﻮن اﻷﺳﺎﳼ اﻟﺬي ﻳ ﺤـﺮك اﻟﻜﺜـ ﻣـﻦ ﻛﻴﻤﻴﺎء ﺗﻴﺘﺎن ﻫﻮ ا ﻴﺜﺎن ﺣﻴﺚ ﻳﻨﻘﺴﻢ ا ﻴﺜﺎن ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟﺘﻴﺘﺎن ﺑﻔﻌﻞ ﺿﻮء اﻟﺸﻤﺲ أو اﻹﻟﻜﱰوﻧــﺎت ا ﻟﻨﺸــﻄﺔ ﻣــﻦ اﻟﻐــﻼف ا ﻐﻨﺎﻃﻴ ـ ﴘ ﻟﺰﺣـﻞ ﺛـﻢ ﻳﺘﺤـﺪ ﻣﺠـﺪد اً ﻣـﻊ ﺟﺰﻳﺌ ﺎت أﺧﺮى ﻟﺘﻜﻮﻳﻦ ﻣﻮاد ﻣﺜﻞ اﻹﻳﺜـﺎن إﱃ ﺟﺎﻧﺐ ﺟﺰﻳﺌﺎت أ ﻛﺜـﺮ ﺗﻌﻘﻴـﺪاً ﺗﺤﺘـﻮي ﻋـﲆ اﻟﻜﺮﺑﻮن . ﻟﻘﺪ و ﻓﺮت ﺑﻴﺎﻧﺎت ﺗﻠﺴﻜﻮب وﻳـﺐ ﺣﻠﻘﺔ ﻣﻔﻘﻮدة أﺳﺎﺳ ﻴﺔ ﰲ ﻓﻬﻤﻨـﺎ ﻟﻠﻌﻤﻠﻴـﺎت اﻟﻜﻴﻤﻴﺎﺋﻴﺔ ، اﻟﻜﺸﻒ اﻟﻨﻬﺎﺋﻲ واﻟﺤﺎﺳـﻢ ﻋـﻦ ﺟﺬر ا ﻴﺜﻴﻞ اﻟﺬي ﻳﺴﻤﻰ " اﺟﺬر " ﻷﻧﻪ ﻳﺤﺘـﻮي ﻋﲆ إﻟﻜﱰون " ﺣﺮ" ﻟﻴﺲ ﰲ راﺑﻄﺔ ﻛﻴﻤﻴﺎﺋﻴـﺔ ﻋﻨﺪ ﺗﻔﻜﻚ ا . ﻴﺜﺎن اﻛﺘﺸﺎف ﻫﺬه ا ﺎدة اﻟﺜﻤﻴﻨﺔ ﻳﻌﻨﻲ أن اﻟﻌﻠﻤﺎء ﻳﻤﻜﻨﻬﻢ رؤﻳﺔ اﻟﺘﻔﺎﻋﻞ اﻟﻜﻴﻤﻴﺎﺋﻲ ﻋﲆ ﺗﻴﺘـﺎن ﻷول ﻣﺮة ﺑﺪﻻً ﻣـﻦ ﻣﺠـﺮد ﻣﻜﻮﻧﺎﺗـﻪ اﻷوﻟﻴـﺔ ﻷول ﻣﺮة ﺑﺪﻻً ﻣـﻦ رؤﻳـﺔ ﻣﻜﻮﻧﺎﺗـﻪ اﻷوﻟﻴـﺔ وﻧﻮاﺗﺠﻪ اﻟﻨﻬﺎﺋﻴـﺔ . ﻓﻘـﻂ ﻗﺎﻟـﺖ ﺳـﺘﻴﻔﺎﻧﻲ ﻣﻴﻼم ا ﺆﻟﻔﺔ ا ﺸﺎرﻛﺔ ﻣـﻦ ﻣ ﺮﻛـﺰ ﺟـﻮدارد ﻟﺮﺣﻼت اﻟﻔﻀﺎء " : ﻷول ﻣـﺮة ﻳ ﻤﻜﻨﻨـﺎ رؤﻳـﺔ اﻟﻜﻌﻜﺔ اﻟﻜ ﻴﻤﻴﺎﺋﻴﺔ أﺛﻨﺎء ارﺗﻔﺎﻋﻬـﺎ ﰲ اﻟﻔـﺮن ﺑﺪﻻً ﻣﻦ ﻣﺠﺮد ﻣﻜ ﻮﻧﺎﺗﻬﺎ اﻷوﻟﻴﺔ ﻣـﻦ اﻟـﺪﻗﻴﻖ واﻟﺴﻜﺮ ﺛﻢ اﻟﻜﻌﻜﺔ اﻟﻨﻬﺎﺋﻴﺔ ا ﺜﻠ ".ﺠﺔ ﻟﻬﺬه اﻟﻜﻴﻤﻴﺎء اﻟﻬﻴﺪروﻛﺮﺑﻮﻧﻴﺔ آﺛـﺎر ﻃﻮﻳﻠـﺔ ا ﺪى ﻋﲆ ﻣﺴﺘﻘﺒﻞ ﺗﻴﺘـﺎن . ﻓﻌﻨـﺪﻣﺎ ﻳﺘﻔﻜـﻚ ا ﻴﺜﺎن ﰲ اﻟﻐﻼف اﻟﺠﻮي اﻟﻌﻠﻮي ﻳﺘﺤﺪ ﺑﻌﻀﻪ ﻣﻜﻮ ﻧﺎً ﺟﺰﻳﺌـﺎت أﺧـﺮى ﺗﺼـﻞ ﰲ اﻟﻨﻬﺎﻳـﺔ إﱃ ﺳﻄﺢ ﺗﻴﺘﺎن ﺑﺸﻜﻞ ﻛﻴﻤﻴﺎﺋﻲ أو آﺧـﺮ ﺑﻴﻨﻤـﺎ ـﺗﺘ ﴪب ﺑﻌﺾ ﺟﺰﻳﺌـﺎت اﻟﻬﻴـﺪروﺟ ﻣـﻦ اﻟﻐﻼف اﻟﺠﻮي وﻧﺘﻴﺠﺔ ﻟﺬﻟﻚ ﺳﻴﻨﻀﺐ ا ﻴﺜﺎن ﺑﻤﺮور اﻟﻮﻗﺖ ﻣﺎ ﻟﻢ ﻳﻜﻦ ﻫﻨـﺎك ﻣﺼـﺪر ﻣـﺎ ﻟﺘﺠﺪﻳﺪه وﺣﺪﺛﺖ ﻋﻤﻠﻴﺔٌ ﻣ ﻤﺎﺛﻠﺔ ﻋـﲆ ا ـﺮﻳﺦ ﺣﻴﺚ ﺗﻔﻜﻜﺖ ﺟﺰﻳﺌﺎت ا ﺎء و ﻓﻘﺪ اﻟﻬﻴﺪروﺟ اﻟﻨﺎﺗﺞ ﰲ اﻟﻔﻀﺎء وﻗﺪ ﻧﺘﺞ ﻋـﻦ ذﻟـﻚ ﻛﻮﻛـﺐ ﺻﺤﺮاوي ﺟﺎفٌ ﻧﺮاه اﻟﻴﻮم . ﻳ ﻌﺪ ا ﻴﺜﺎن ﻋﲆ ﺗﻴﺘﺎن ﻣﺎدة ﻗﺎﺑﻠﺔ ﻟﻼﺳـ ﺘﻬﻼك ﻣﻦ ا ﻤﻜﻦ أن ﻳﺘﺠﺪد ﺑﺎﺳﺘﻤﺮار وﻳﺘﺼﺎﻋﺪ ﻣﻦ اﻟﻘﴩة اﻟﺪاﺧﻠﻴﺔ ﻋﲆ ﻣﺪى ﻣﻠﻴـﺎرات اﻟﺴـﻨ وإﻻ ﻓﺴﻴﺨﺘﻔﻲ ﰲ اﻟﻨﻬﺎﻳﺔ وﺳﻴﺼـﺒﺢ ﺗﻴﺘـﺎن ﻋﺎ ًﺎ ﺷﺒﻪ ﺧﺎلٍ ﻣـﻦ اﻟﻬـﻮاء، ﻣﻠﻴﺌًـﺎ ﺑﺎﻟﻐﺒـﺎر وإﻻ ﻓﺴﻴﺨﺘﻔ ﻲ ﰲ اﻟﻨﻬﺎﻳﺔ وﺳﻴﺼـﺒﺢ ﺗﻴﺘـﺎن ﻋﺎ ًﺎ ﺷﺒﻪ ﺧـﺎلٍ ﻣـﻦ اﻟﻬـﻮاء ﻣﻠﻴﺌـﺎً ﺑﺎﻟﻐﺒـﺎر واﻟﻜﺜﺒﺎن اﻟﺮﻣﻠﻴﺔ ﻛﻤﺎ ﻗﺎل ﻧﻴﻜﺴﻮن . ﻫﺬه اﻟﺼﻮرة ا ﺴﺘﻘﺒﻠﻴﺔ ﻟﺘﻴﺘﺎن أﻛـﱪ أﻗﻤـﺎر زﺣﻞ ﺗﺜ ﻓﻀﻮل اﻟﻌﻠﻤﺎء ﺣﻮل ﻛﻴﻔﻴﺔ ﺗﻄﻮره وﺗﻐ ه ﺑﻤﺮور اﻟﺰﻣﻦ . ﻻﺳﺘﻜﺸﺎ ف ا ﺰﻳﺪ ﻣـﻦ أﴎار ﺗﻴﺘﺎن ﺳﺘﻨﻄﻠﻖ ﻣﻬﻤﺔ دراﻏـﻮن ﻓـﻼ ي اﻟﺘﺎﺑﻌﺔ ﻟ ﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ وﻫـﻲ ﻣﺮﻛﺒـﺔ ﻣﺮوﺣﻴـﺔ آﻟﻴﺔ ﻣﻦ ا ﻘﺮر أن ﺗﻬﺒﻂ ﻋﲆ ﻗﻤﺮ زﺣـﻞ ﻋـﺎم 2034 . ﺳﺘﺴﺘﻜﺸﻒ دراﻏﻮ ن ﻓﻼي ﻣﺠﻤﻮﻋﺔ ﻣﺘﻨﻮﻋﺔ ﻣﻦ ا ﻮاﻗﻊ ﻟﺘﻘﺪم ﻟﻨـﺎ ﻧﻈـﺮة ﻓ ﺮﻳـﺪة وﻣﻔﺼﻠﺔ ﻋـﻦ ﺳـﻄﺤﻪ وﺗﻜﻮﻳﻨـﻪ وﺳـﺘﻜﻤﻞ ﺗﺤﻘﻴﻘﺎﺗﻬــﺎ ا ﺘﻌﻤﻘــﺔ ا ﻨﻈــﻮر اﻟﻌــ ﺎ ﻲ ﻟﺘﻠﺴﻜﻮب و وﻳﺐ ﻫـﺬا اﻟﺘﻌـﺎون ﺑـ ا ﻬـﺎم اﻷرﺿﻴﺔ واﻟﻔﻀﺎﺋﻴﺔ ﻳﻌﻜﺲ اﻟﺘـﺰام ا ﺠﺘﻤـﻊ اﻟﻌﻠﻤـﻲ ﺑﻔﻬـﻢ أﻋﻤـﻖ ﻟﻸﺟـ ﺮام اﻟﺴـﻤﺎوﻳﺔ . أﺿﺎﻓﺖ ﻫﺎﻳﺪي ﻫﺎﻣﻴﻞ ﻧﺎﺋﺒﺔ رﺋـﻴﺲ ﺟﻤﻌﻴـﺔ اﻟﺠﺎﻣﻌـﺎت ﻟﻠﺒﺤـﻮث ﰲ ﻋﻠـﻢ اﻟﻔﻠـﻚ وﻋﺎ ـ ﺔ ﻣﺘﻌﺪدة اﻟﺘﺨﺼﺼﺎت ﰲ ﻣﻬﻤﺔ ﺗﻠﺴﻜﻮب وﻳﺐ ﰲ ﺗﻌﻠﻴﻖٍ ﺑﺎﻟﻎ اﻷﻫﻤﻴﺔ ﻣ: " ﻦ ﺧﻼل اﻟﺠ ﻤﻊ ﺑ ﻛﻞ ﻫﺬه ا ﻮارد ﺑﻤـﺎ ﰲ ذﻟـﻚ ﺗﻠﺴـﻜﻮب وﻳـﺐ وﺗﻠﺴﻜﻮ ب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ وا ﺮاﺻﺪ اﻷرﺿﻴﺔ ﻳﻀﻤﻦ ﻫﺬا اﻟﺘﻌﺎون اﻟﻔﺮﻳﺪ ﻋـﺪم ﻓﻘـﺪان أي ﺑﻴﺎﻧﺎت ﻗﻴﻤﺔ وﻳﺴﻤﺢ ﻟﻠﻌﻠﻤﺎء ﺑﺒﻨـﺎء ﺻـﻮرة ﺷﺎﻣﻠﺔ ﻋﻦ ﺗﻴﺘﺎن ﻋـﱪ ﻋﻘـﻮد ﻣـﻦ ا ﺮاﻗﺒـﺔ واﻻﺳﺘﻜﺸﺎف وﻳﻔـﺘﺢ آﻓﺎﻗـ ﺎً ﺟﺪﻳـﺪة ﻟﻔﻬـﻢ ﺗﺮﻛﻴﺒﺘ ـﻪ اﻟﺠﻴﻮﻟﻮﺟﻴ ـﺔ وﻇﺮوﻓ ـﻪ ا ﻨﺎﺧﻴــﺔ وإﻣﻜﺎﻧﻴﺔ وﺟﻮد أي أﺷﻜ ﺎل ﻣﻦ أﺷﻜﺎل اﻟﺤﻴﺎة اﻟﻜﺎﻣﻨﺔ ﻓﻴﻪ ". ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 5 ﻳﻮﺟــــــﺪ ــــــﻚ ﻋﻠــــــﻰ ار ﻔــــــﺎع ﻣﺮﺻـــــﺪ د ﻠﻴــــــﻮ إم ﻛ 4.145 ) اً ﻣــ 13.600 ( ﻗـــﺪم ـــﺎﻟﻘﺮ ﻣـــﻦ ﻗﻤـــﺔ ـﺎ ﻓـﻲﻫـﺎواي ﻣﺎوﻧـﺎ ﻛ . ـﺎب اﻟﻤﺮﺻــﺪ ﺗﺤﺘـﻮيﻗ ر ﺴـــــــ ﺘ ﻤـــــــﺮآﺗ ﺗــــــﻮأﻣ ﻋﻠــــــﻰ ﺗﻠﺴـــــــ ﻮﺑ ﻗﻄﺮ ﻞ ﻣﻨﻬﻤﺎ 10 أﻣﺘﺎر )33 (. ﻗﺪﻣﺎً [W.M. KeckObservatory] 50