Free Astronomy Magazine November-December 2025 ARABIC VERSION

portant role in the formation of cloudswithintheiratmospheres.De- spitedecadesofsearching,iteluded detection in the atmospheres of our SolarSystem’sgasgiants,Jupiterand Saturn, as well as the thousands of atmospheres scientists have studied on brown dwarfs and gas giants around other stars. This marks the firstdiscoveryofsilaneinanybrown dwarf, exoplanet, or Solar System object. The fact that this molecule hasn’t been detected anywhere ex- cept in a single, peculiar brown dwarf suggests something about the chemistry occurring in such ancient environments. “Sometimes it’s the extreme objects that help us under- stand what’s happening in the aver- age ones,” says Jackie Faherty, a researcher at the American Museum of Natural History in New York City and lead author on the paper. Locatedabout50light-yearsfrom Earth, The Accident likely formed 10–12 billion years ago, making it oneoftheoldestbrowndwarfsever discovered.TheUniverseisnearly14 billionyearsold,meaningthatThe Accidentformedatatimewhenthe cosmos contained mostly hydrogen and helium, with trace amounts of other elements, including silicon. Overeons,elementslikecarbon,ni- trogen, and oxygen formed in the coresofstars,meaningthatplanets andstarsthatformedmorerecently possessmoreofthoseelements.The presenceofsilaneinTheAccident’s atmosphere suggests that, in veryoldobjects,siliconcanbondwithhy - drogen to form a light molecule that can reach the upper layers of a gas giant’s atmosphere. But in objects that formed more recently, like JupiterandSaturn,thesiliconbonds with the more readily available oxy- gen,creatingheaviermoleculesthat sink deep below the surface layersof the atmosphere, where they are undetectable by our telescopes. The evidence uncovered in The Ac- cident’s atmosphere confirms as- tronomers’ understanding of how clouds on gas giants form, and of- ferscriticalinsightintohowprimor- dialformationcanimpactthecom- position of a planet’s atmosphere. Additionally,itrevealshowaworld formed many billions of years ago canlookdrasticallydifferentthana world formed during the dawn of ourSolarSystem.     NOVEMBER-DECEMBER2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 22 ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 5 وﺗﻔﺴ اﻟﻌﻤﻠﻴﺎت اﻟﻜﻴﻤﻴﺎﺋﻴﺔ اﻟﻘﺪﻳﻤﺔ . ﻋـﲆ اﻟﺮﻏﻢ ﻣـﻦ ﻋﻘـﻮد ﻣـﻦ اﻟﺒﺤـﺚ ﺑﻤـﺎ ﰲ ذﻟـﻚ اﻻﻛﺘﺸﺎﻓ ﺎت ﰲ أﺟﻮا ء ﻋﻤﺎﻟﻘﺔ اﻟﻐﺎز ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ ﻣﺜﻞ ا ﺸﱰي وزﺣـﻞ ﺑﺎﻹﺿـﺎﻓﺔ إﱃ آﻻف اﻷﻏﻠﻔﺔ اﻟﺠﻮﻳﺔ اﻟﺘـﻲ درﺳـﻬﺎ اﻟﻌﻠﻤـﺎء ﻟﻸﻗﺰام اﻟﺒﻨﻴﺔ واﻟﻌﻤﺎﻟ ﻘﺔ اﻟﻐﺎزﻳﺔ ﺣﻮل اﻟﻨﺠﻮم اﻷﺧﺮى ﻤﺜﻳ. ﻞ ﻫﺬا أول اﻛﺘﺸـﺎف ﻟ ﻠﺴـﻴﻼن ﰲ أي ﻗﺰم ﺑﻨﻲ أو ﻛﻮﻛـﺐ ﺧـﺎرﺟﻲ أو ﰲ ﺟـﺮم اﻟﻨﻈﺎم اﻟـ . ﺸﻤﴘـ إن ﻋـﺪم اﻛﺘﺸـﺎف ﻫـﺬا اﻟﺠﺰيء ﰲ أي ﻣﻜ ﺎن ﺑﺎﺳﺘﺜﻨﺎء ﻗﺰم ﺑﻨﻲ واﺣﺪ ﻏﺮﻳﺐ ﻳ ﺸ إﱃ ﳾء ﻣﺎ ﻳﺘﻌﻠﻖ ﺑﺎﻟﻜﻴﻤﻴﺎء اﻟﺘﻲ ﺗﺤﺪث ﰲ ﻣﺜﻞ ﻫﺬه اﻟﺒﻴﺌﺎت اﻟﻘﺪﻳﻤﺔ . ﺗﻘـﻮل ﺟـﺎﻛﻲ ﻓـﺎﻫﺮﺗﻲ اﻟﺒﺎﺣﺜـﺔ ﰲ ا ﺘﺤـﻒ اﻷﻣﺮﻳﻜﻲ ﻟﻠﺘﺎرﻳﺦ اﻟﻄﺒﻴﻌﻲ ﰲ ﻣﺪﻳﻨﺔ ﻧﻴﻮﻳﻮرك وا ﺆﻟﻔﺔ اﻟﺮﺋﻴﺴﻴﺔ ﻟﻠﺪراﺳﺔ " : أﺣﻴﺎﻧ ﺎً ﺗﺴﺎﻋﺪﻧﺎ اﻷﺟﺮام ا ﺘﻄﺮﻓـﺔ ﻋـﲆ ﻓﻬـﻢ ﻣـﺎ ﻳﺤـﺪث ﰲ اﻷﺟﺮام ا ﺘﻮﺳﻄﺔ ﻳﻘﻊ ". اﻟﻘﺰم اﻟﺒﻨﻲ اﻟﻘﺪﻳﻢ " اﻟﺤـﺎدث ﻋــﲆ " ﻣﺴـﺎﻓﺔ ﺣـﻮاﱄ 50 ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻣﻦ اﻷرض وﻣﻦ ا ﺮﺟﺢ أﻧـﻪ ﺗﺸـﻜ ﻞ ﻗﺒﻞ 10-12 ﻣﻠﻴﺎر ﺳﻨﺔ ﻣﻤﺎ ﻳﺠﻌﻠﻪ ﻣﻦ أﻗـﺪم اﻷﻗﺰام اﻟﺒﻨﻴﺔ ا ﻜﺘﺸﻔﺔ ﻋﲆ اﻹﻃـﻼق . ﻳﺒﻠـﻎ ﻋﻤﺮ اﻟﻜﻮن ﻣﺎ ﻳﻘﺮب ﻣﻦ 14 ﻣﻠﻴﺎر ﺳﻨﺔ ﻣﻤﺎ ﻳﻌﻨﻲ أن اﻟﺼﺪﻓﺔ " " ﺗﺸﻜّﻠﺖ ﰲ وﻗﺖ ﻛﺎن ﻓﻴﻪ ﻋﻤﺮ اﻟﻜﻮن ﻣﺎ ﻳ ﻘﺮب ﻣﻦ 14 ﻣﻠﻴﺎر ﺳﻨﺔ ﻣﻤﺎ ﻳﻌﻨـﻲ أن اﻟﻘـﺰم اﻟﺒﻨـﻲ اﻟﻘـﺪﻳﻢ " اﻟﺤـﺎدث " ﺗﺸﻜﻞ ﰲ وﻗﺖ ﻛـﺎن ﻓﻴـﻪ اﻟﻜـﻮن ﻳﺤﺘـﻮي ﰲ اﻟﻐﺎﻟﺐ ﻋﲆ اﻟﻬﻴﺪروﺟ ﻮم واﻟﻬﻠﻴ ﻣﻊ ﻛﻤﻴﺎت ﺿـﺌﻴﻠﺔ ﻣــﻦ ﻋﻨ ـﺎﴏ أﺧــﺮى ﺑﻤ ـﺎ ﰲ ذﻟ ـﻚ اﻟﺴﻴﻠﻴﻜﻮن . ﻋﲆ ﻣﺮ اﻟﻌﺼﻮر ﺗﻜﻮﻧﺖ ﻋﻨﺎﴏ ﻣﺜﻞ اﻟﻜﺮﺑﻮن واﻟﻨﻴﱰوﺟ واﻷﻛﺴﺠ ﰲ ﻧﻮى اﻟﻨﺠﻮم ﻣﻤﺎ ﻳﻌﻨﻲ أن اﻟﻜﻮاﻛﺐ واﻟﻨﺠﻮم اﻟﺘـﻲ ﺗﺸﻜﻠﺖ ﻣﺆﺧﺮاً ﺗﺤﺘﻮي ﻋﲆ ا ﺰﻳﺪ ﻣـﻦ ﻫـﺬه اﻟﻌﻨﺎﴏ . ﻳﺸـ وﺟـﻮد اﻟﺴـﻴﻼن ﰲ اﻟﻐـﻼف اﻟﺠــﻮي ﻟــ " اﻟﺤـﺎدث " إﱃ أﻧـﻪ ﰲ اﻷﺟﺴـﺎم اﻟﻘﺪﻳﻤﺔ ﺟﺪ اً ﻳﻤﻜﻦ ﻟﻠﺴﻴﻠﻜﻮن أن ﻳﱰاﺑﻂ ﻣﻊ اﻟﻬﻴﺪروﺟ ﻟﺘﻜﻮﻳﻦ ﺟـﺰيء ﺧﻔﻴـﻒ اﻟـﻮزن ﻳﻤﻜﻨﻪ اﻟﻮﺻﻮل إﱃ اﻟﻄﺒﻘﺎت اﻟﻌﻠﻴﺎ ﻣﻦ اﻟﻐﻼف ﻳﻤﻜﻨﻪ اﻟﻮﺻﻮل إﱃ اﻟﻄﺒﻘﺎت اﻟﻌﻠﻴﺎ ﻣﻦ اﻟﻐﻼف اﻟﺠﻮي ﻟﻜﻮﻛﺐ ﻏﺎزي ﻋﻤﻼق ﻟ. ﻜﻦ ﰲ اﻷﺟﺮام اﻟﺘﻲ ﺗﺸﻜﻠﺖ ﻣﺆﺧﺮاً ﻣﺜـﻞ ﻛـﻮﻛﺒﻲ ا ﺸـﱰي وزﺣـﻞ ﻳـﱰاﺑﻂ اﻟﺴـﻴﻠ ﻜﻮن ﻣـﻊ اﻷﻛﺴـﺠ ا ﺘﻮﻓﺮ ﺑﺴﻬﻮﻟﺔ ﻣﻜﻮﻧ ﺎً ﺟﺰﻳﺌﺎت أﺛﻘﻞ ﺗﻐﻮص ﺎً ﻋﻤﻴﻘــ ﺗﺤــﺖ ﻃﺒﻘــﺎت اﻟﻐــﻼف اﻟﺠــﻮي اﻟﺴــﻄﺤﻴﺔ ﺣﻴــﺚ ﻻ ﻳﻤﻜــﻦ ﻟ ﺘﻠﻠ ﺴــﻜﻮﺑﺎت رﺻﺪﻫﺎ . ﻳﺆﻛﺪ اﻟﺪﻟﻴﻞ ا ﻜﺘﺸﻒ ﰲ ﻏﻼف اﻟﻘﺰم اﻟﺒﻨﻲ اﻟﻘﺪﻳﻢ اﻟﺤﺎدث " " اﻟﺠﻮي ﻓﻬﻢ ﻋﻠﻤـﺎء اﻟﻔﻠﻚ ﻟﻜﻴﻔﻴﺔ ﺗﺸﻜﻞ اﻟﺴ ﺤﺐ ﻋـﲆ اﻟﻜﻮاﻛـﺐ اﻟﻐﺎزﻳﺔ اﻟﻌﻤﻼﻗﺔ وﻳﻘﺪم رؤﻳﺔ ﺣـﻮل ﻛﻴﻔﻴـﺔ ﺗﺄﺛ اﻟﺘﻜﻮﻳﻦ اﻟﺒﺪاﺋﻲ ﻋـﲆ ﺗﺮﻛﻴـﺐ اﻟﻐـﻼف اﻟﺠﻮي ﻟﻠﻜﻮﻛﺐ . ﺑﺎﻹﺿﺎﻓﺔ إﱃ ذﻟﻚ ﻳﻜﺸﻒ ﻋﻦ أن ﻋﺎ ﺎً ﺗﺸﻜﻞ ﻗ ﺒﻞ ﻣﻠﻴﺎرات اﻟﺴﻨ ﻗﺪ ﻳﺒـﺪو ﺎً ﺨﺘﻠﻔـ ﻣ ﺎً ﺗﻤﺎﻣـ ﻋـﻦ ﻋـﺎﻟﻢ ﺗﺸـﻜﻞ ﰲ ﻓﺠــﺮ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ . ﻳﺸ ﻫـﺬا اﻻﻛﺘﺸـﺎف إﱃ أن ﺗﻄـﻮر اﻟﻐـﻼف اﻟﺠﻮي ﻟﻠﻜﻮاﻛﺐ ﻳﺘﺄﺛﺮ ﺑﺸﻜﻞ ﻛﺒـ ﺑﻈـﺮو ف ﻧﺸﺄﺗﻬﺎ اﻷوﻟﻴﺔ . ﻛﻤﺎ ﻳﻔﺘﺢ آﻓﺎﻗ ﺎً ﺟﺪﻳﺪة ﻟﻔﻬﻢ ﺗﻨﻮع اﻟﻌﻮاﻟﻢ اﻟﺨﺎرﺟﻴﺔ وا ﺴﺎﻋﺪة ﰲ اﻟﺒﺤـﺚ ﻋﻦ ﻛﻮاﻛﺐ ﻗﺎﺑﻠﺔ ﻟﻠﺤﻴﺎة ﰲ اﻟﻜﻮن . اﻷﻗـــﺰام ـــﺔ اﻟ ﻨ أﺿـــ ﻢ ﻣـــﻦ اﻟ ﻮاﻛـــﺐ ﻟﻜﻨﻬـــﺎ ـــــﻨﻔﺲﺿـــــﺨﺎﻣﺔ اﻟﻨﺠـــــﻮم ﻟ ﺴـــــﺖ . ﺸـــــ ﻞ ﻋـــــﺎم ﺗـــــــــ اوح ﻛﺘﻠﺘﻬـــــــــﺎ ﺑـــــــــ 13 و 80 ﺿـــــــــﻌﻒﻛﺘﻠـــــــــ ﺔ اﻟﻤﺸـــ ي . ﻧ ﻤـــ ـــ ﺼـــﺒﺢ اﻟﻘـــﺰم اﻟ ﺎً إذا ار ﻔـــﻊ ﺿﻐﻂ ﻧﻮاﺗﮫ ﻤﺎ ﻜﻔﻲ ﻟ ﺪء اﻻﻧﺪﻣﺎج اﻟﻨﻮوي ﻣﻤـــﺎ إﻟـــﻰ إﻃـــﻼقﻃﺎﻗـــﺔ وﺿـــﻮء ﻳـــﺆد ﺸـــ ﻞ . ﻣﺴﺘﻤﺮ [NASA/JPL-Caltech]