Free Astronomy Magazine July-August 2025 ARABIC VERSION

Evidence of cloud convection in Titan’s northern hemisphere byNASA/ESA/CSA ChristinePulliam aturn’smoonTitanisanin- triguing world cloaked in a yel- lowish, smoggy haze. Similar to Earth, the atmosphere is mostly ni- trogen and has weather, includingclouds and rain. Unlike Earth, whose weatherisdrivenbyevaporating and condensing water, frigid Titan has a methane cycle. NASA’s James WebbSpaceTelescope,supple- mented with images from the KeckII telescope, has for the first timefound evidence for cloud convection inTitan’snorthernhemisphere,over a region of lakes and seas. Webbalso has detected a key carbon-con- tainingmoleculethatgivesinsight into the chemical processes in Ti- tan’s complex atmosphere. On Ti- tan,methaneplaysasimilarroleto JULY-AUGUST2025 رﺻﺪ ـ ﻤﻞ ﺤﺮاري ﺳﺤﺎﺑﻲ ﻓﻲ ﺷﻤﺎل ﺗ ﺘﺎن : ﻘﻠﻢ ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ ﻳﻮﺿﺢ اﻟﺮﺳﻢ اﻟﺒ ﺎﻧﻲ أﻋﻼﻩ، اﻟﻤ ﻮن ﻣﻦ أرﻊ ﻟﻮﺣﺎت ﻋﻤﻠ ﺔ ﻛ ﻤ ﺎﺋ ﺔ ر ﺴ ﺔ ُﻌﺘﻘﺪ أﻧﻬـﺎ ﺗﺤـﺪث ﻓـﻲ اﻟﻐــﻼف اﻟــ ـ ﺠﻮي ﻟﻘﻤــﺮ زﺣــﻞ، ﺗ ﺘـــﺎن .١ ( ﺘﻤﺘــﻊ ﺗ ﺘــﺎن ﻐــﻼفﺟـــﻮيﺳــﻤ ﻚ ﻣــﻦ اﻟﻨ وﺟــ )N2 ( ﻳﺤﺘـــﻮي أ ﻀًﺎ ﻋﻠﻰ اﻟﻤ ﺜﺎن ) CH4). 2 ( ﺗﺘﺸ ﻞ ﺟﺰ ﺌﺎت ﺗُﻌﺮف ﺎﺳﻢﺟﺬور اﻟﻤ ﺜﻴﻞ ) CH3 ( ﻋﻨﺪﻣﺎ ﺘﻔ ﻚ اﻟﻤ ﺜـﺎن ﻔﻌﻞ ﺿﻮء اﻟﺸﻤﺲ أو اﻹﻟﻜ وﻧﺎت اﻟﻨﺸﻄﺔ ﻣﻦ اﻟﻐﻼف اﻟﻤﻐﻨﺎﻃ ﺴﻲ ﻟﺰﺣﻞ .3 ( ﺛـﻢ ﺘﺤـﺪ ﻣـﻊ ﺟﺰ ﺌـﺎت ــﻮﻳﻦ ﻣــﻮاد ﻣﺜــﻞ اﻹ ﺜــﺎ أﺧــﺮى أو ﻣــﻊ ﻧﻔﺴــﮫ ﻟﺘ )ن C2H6). 4 ( ﺘﻜﺜــﻒ اﻟﻤ ﺜــﺎن واﻹ ﺜــﺎن وﺟﺰ ﺌــﺎت أﺧـــﺮى و ﺘﺴـﺎﻗﻄﺎن ﻣـﻦ اﻟﻐــﻼف اﻟـ ـ ﺠﻮي ـﻮﻧ ﻣ ﺑﺤــ ات وﺑﺤـﺎر اً ﻋﻠـﻰﺳـﻄﺢ ﺗ ﺘـﺎن وﻗـﺪ رﺻــ ﺪ ﺗﻠﺴـ ﻮبﺟــ ﻤﺲ ــﺐ اﻟﻔﻀـــﺎﺋﻲ اﻟﺘــﺎﺑﻊ ﻟﻮ ﺎﻟـــﺔ ﻧﺎﺳـــﺎ ﺟــﺬور اﻟﻤ ﺜﻴـــﻞ ﻋ و ﻠــﻰ ﺗ ﺘـــﺎن ﻷول ﻣـــﺮة، ﻣﻤــﺎ ﻳـــﻮﻓﺮﺟــﺰء اً أﺳﺎﺳـــ ﺎً ﻣـــﻦ ﻓﻬﻤﻨﺎ ﻟﻠﻌﻤﻠ ﺎت اﻟﻜ ﻤ ﺎﺋ ﺔ ﻟﺘ ﺘﺎن . [NASA, ESA, CSA, ElizabethWheatley (STScI)] ﻗﻤـﺮ زﺣﻞ ﺗﻴﺘﺎن ﻫﻮ ﻋـﺎﻟﻢ ﻣﺜـ ﻟﻼﻫﺘﻤـﺎم ﻳﻜﺘﻨﻔﻪ ﻃﺒﻘﺔ ﻣﻦ اﻟـﺪﺧﺎن و ﻣﺎﺋﻠـﺔ ﺿـﺒﺎب ﻟﻠ ة وﻣﺜﻞ ﺼﻔﺮ اﻷرض ﻳﺘﻜﻮن ﻏﻼﻓ ﻪ اﻟﺠﻮي ﰲ اﻟﻐﺎﻟﺐ ﻣﻦ اﻟﻨﻴﱰوﺟ وﻟـﻪ ﻃﻘـﺲ ﻳﺸـﻤﻞ اﻟﻐﻴﻮم واﻷﻣﻄﺎر وﻟﻜـﻦ ﻋـﲆ ﻋﻜـﺲ اﻷرض اﻟﺘ ﻲ ﻳﻌﺘ ﻤﺪ ﻃﻘﺴﻬﺎ ﻋﲆ ﺗﺒﺨﺮ ا ﺎء وﺗﻜﺜﻴﻔـﻪ ﻓﺈ ن ﺗﻴﺘﺎن ا ﺘﺠﻤﺪ ﻟﻪ دورة ﻣﻴﺜﺎن وﻗﺪ وﺟـﺪ ﺗﻠﺴـﻜﻮب ﺟـﻴﻤﺲ وﻳـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ﻣﺪﻋﻮﻣ ﺎ ﺑﺼـﻮر ﻣـﻦ ﺗﻠﺴـﻜﻮب ﻛﻴﻚ ﻷول ﻣﺮة دﻟـﻴﻼً ﻋـﲆ اﻟﺤﻤـﻞ اﻟﺤـﺮاري ﻟﻠ اﻟ ﺴـﺤﺐ ﰲ ﻨﺼـﻒ اﻟﺸـﻤﺎﱄ ﻟﺘﻴﺘـﺎن ﻓـﻮق ﻣﻨﻄﻘﺔ ﻣﻦ اﻟﺒﺤ ات واﻟﺒﺤﺎر . ﻛﻤﺎ اﻛﺘﺸـﻒ ﺗﻠﺴﻜﻮ ب وﻳﺐ ﺟﺰﻳﺌًﺎ رﺋﻴﺴـﻴًﺎ ﻳﺤﺘـﻮي ﻋـﲆ ﺗﻠﺴﻜﻮب وﻳﺐ ﺟﺰﻳﺌ ﺋﻴﺴـﻴﺎُ ر ﺎُ ﻳﺤﺘـﻮي ﻋـﲆ اﻟﻜﺮﺑﻮن ﻣﻤﺎ ﻳ ﻌﻄـﻲ ﻓﻜـﺮةً ﻋـﻦ اﻟﻌﻤﻠﻴـﺎت اﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﰲ اﻟﻐﻼف اﻟﺠﻮي ا ﻌﻘـﺪ ﻟﺘﻴﺘـﺎن . ﻳﻠﻌﺐ ا ﻴﺜﺎن ـــــ ﻳﻠﻌﺐ ا ﻴﺜﺎن ﻋﲆ ﺗﻴﺘﺎن اً دور ﺎُ ﻣﺸـﺎﺑﻬ ﻟﻠﻤـﺎء ﻋﲆ اﻷرض ﻓﻴﻤﺎ ﻳﺘﻌﻠﻖ ﺑﺎﻟﻄﻘﺲ . ﻳﺘﺒﺨﺮ ﻣ ﻦ اﻟﺴﻄﺢ وﻳﺮﺗﻔـﻊ إﱃ اﻟﻐـﻼف اﻟﺠـﻮي ﺣﻴـﺚ ﻳﺘﻜﺜﻒ ـ ـــــ ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 5