Free Astronomy Magazine July-August 2025 ARABIC VERSION

wateronEarthwhenitcomesto weather. It evaporates from the sur- face and rises into the atmosphere, where it condenses to form meth- ane clouds. Occasionally it falls as a chilly, oily rain onto a solid surface where water ice is hard as rocks. “Titan is the only other place in our solar system that has weather like Earth,inthesensethatithasclouds andrainfallontoasurface,” ex- plained lead author Conor Nixon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. TheteamobservedTitaninNovem- ber 2022 and July 2023 using both Webb and one of the twin ground- basedW.M.KeckObservatoriestel- escopes.Thoseobservationsnotonly showed clouds in the mid and high northern latitudes on Titan — the hemisphere where it is currently summer — but also showed those cloudsapparentlyrisingtohigher altitudesovertime.Whileprevious studies have observed cloud convec- tionatsouthernlatitudes,thisisthe firsttimeevidenceforsuchconvec- tionhasbeenseeninthenorth.This issignificantbecausemostofTitan’s lakes and seas are located in its northernhemisphereandevapora- tionfromlakesisamajorpotential methanesource.Theirtotalareais similartothatoftheGreatLakesin North America. OnEarththelowestlayeroftheat- mosphere,ortroposphere,extends up to an altitude of about 7 miles (12kilometers).However,onTitan, ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 49 ﺗــﻢ ــﺐ اﻟﻔﻀــﺎﺋﻲ اﻟﺘــﺎﺑﻊ ﻟﻮ ﺎﻟــﺔ ﻧﺎﺳــﺎ ﻓــﻲ اﻟﺘﻘــﺎطﻫــﺬﻩ اﻟﺼــﻮرﻟﺘ ﺘـﺎن ﺑﻮاﺳــﻄﺔ ﺗﻠﺴــ ﻮبﺟــ ﻤﺲو 11 ﻳﻮﻟﻴــﻮ 2023 ) اﻟﺼــﻒ اﻟﻌﻠـﻮي ( وﻣﺮاﺻــﺪ إم . ــﻚ ﻓــﻲ ﻛ 14 ﻳﻮﻟﻴــﻮ 2023 ) ا ﻟﺼــﻒ اﻟﺴــﻔﻠﻲ .( ﺗﻈﻬــﺮﻫــﺬﻩ اﻟﺼﻮرﺳﺤﺐ اﻟﻤ ﺜﺎن ) اﻟﻤﺸﺎر إﻟﻴﻬﺎ ﺎﻟﺴﻬﺎم اﻟﺒ ﻀﺎء ( ﺗﻈﻬﺮ ﻋﻠﻰ ار ﻔﺎﻋﺎت ﻣﺨﺘﻠﻔﺔ ﻓﻲ اﻟ اﻟ ﻨﺼﻒ اﻟﺸـــﻤﺎﻟﻲ ﻟﺘ ﺘــــﺎن . ـ ﻋﻠــــﻰ اﻟــــ ــــﻼ اﻟﺘﻠﺴــــ ﻮﺑ ــــﺔ ﻣـــﻦ ﺠﺎﻧﺐ اﻷ ﺴـــﺮﺗﻮﺟــــﺪ ﺻــــﻮرﻣﻠﻮﻧــــﺔ ﺗﻤﺜ ﻠ . ﻓــــﻲﺻــــﻮرة ﺗﻠﺴـــــ ﻮب ـــــﺐ اﻟﻀـــــﻮء ﻋﻨـــــﺪ و 1.4 ـــــﺎﻷزرق و ﻣ ﻜـــــﺮون ﻣﻠـــــﻮن 1.5 ﻣ ﻜـــــﺮون أﺧﻀـــــ ﺮو 2.0 ﻣ ﻜـــــﺮون أ ﻤـــــﺮ ) ﻣﺮﺷــﺤﺎت F140M و F150W و F200W ﻋﻠـــﻰ اﻟﺘـــﻮاﻟﻲ .( ـــﻚ اﻟﻀـــﻮء ﻋﻨـــﺪ ﻓـــﻲﺻـــﻮرة ﻛ 2.13 ﻣ ﻜـــﺮون ﻣﻠﻮن ﺎﻷزرق و 2.12 ﻣ ﻜﺮون أﺧﻀـﺮ و 2.06 ﻣ ﻜـﺮون أ ﻤـﺮ ) H2O ، Kp ، و He1b ، ﻋﻠـﻰ اﻟﺘـﻮاﻟﻲ .( ﻓـﻲ اﻟﻌﻤــﻮد اﻷوﺳــﻂ ﺗﻮﺟــﺪ ﺻــﻮر ذاتﻃــﻮل ﻣــﻮﺟﻲواﺣــﺪ اﻟﺘﻘﻄﺘﻬــﺎ ﺗﻠﺴــ ﻮب ــﺐ و وﻣﺮﺻــﺪ ــﻚ ﻛ 2 ﻨــﺪ ﻋ 2.12 . ﻣ ﻜـــﺮون ﻫــــﺬا اﻟﻄــــﻮل اﻟﻤـــﻮﺟﻲﺣﺴــــﺎس ﻟﻼﻧ ﻌﺎﺛــــﺎت ﻣــــﻦ ﻃ ﻘـــﺔ اﻟ وﺑﻮﺳــــﻔ اﻟﺴــــﻔﻠ ﺔ ﻟﺘ ﺘــــﺎن . اﻧ ﻌﺎﺛـﺎ ﻋﻨـﺪ ﺗﻈﻬـﺮاﻟﺼــﻮراﻟﻤﻮﺟـﻮدة ﻓــﻲ أﻗﺼـﻰ اﻟ ﻤــ 1.64 ـﺐ) ﻣ ﻜــﺮون و( و 2.17 ــﻚ) ﻣ ﻜــﺮون ( ﻛ ﻣﻤــﺎ ﻔﻀـــﻞ اﻻر ﻔﺎﻋـــﺎت اﻷﻋﻠـــﻰﻓــﻲﻃ ﻘـــﺔ اﻟ وﺑﻮﺳـــﻔ واﻟﺴ اﺗﻮﺳـــﻔ ﻟﺘ ﺘــﺎن ) ـــﺔ ﻓـــﻮق ﻃ ﻘـــﺔ ﺟﻮ اﻟ وﺑﻮﺳــﻔ .( ﻈﻬــﺮﻫــﺬا أن اﻟﺴــﺤﺐ ﺗُــﺮىﻋﻠــﻰ ارﻔــﺎع أﻋﻠــﻰﻓــﻲ 14 ــﺎﻟﻴﻮم اﻟﺴـــﺎﺑﻖ ﻳﻮﻟﻴــﻮ ﻣﻘﺎرــﺔ ﻓﻲ 11 ﻳﻮﻟﻴﻮ ﻣﻤﺎ ﺪل ﻋﻠﻰ اﻟ ـ ﺤﺮﻛﺔ اﻟﺼﺎﻋﺪة .[NASA,ESA,CSA,STScI,KeckObservatory] ﻳﺘﻜﺜﻒ ﻣُﺸﻜﻼً ﺳﺤﺐ ا ﻴﺜﺎن . أﺣﻴﺎﻧًﺎ ﻳﺘﺴﺎﻗﻂ ا ﻄﺮ اﻟﺒﺎرد اﻟﺰﻳﺘﻲ ﻋﲆ ﺳﻄﺢ ﺻـﻠﺐ ﺣﻴـﺚ ﻳﻜﻮن اﻟﺠﻠﻴﺪ ا ﺎﺋﻲ ﺻﻠ ﺎً ﺒ ﻛﺎﻟﺼﺨﻮر . أوﺿﺢ اﻟﺒﺎﺣﺚ اﻟﺮﺋﻴﴘ ﻛﻮﻧﻮر ﻧﻴﻜﺴﻮن ﻣـﻦ ﻣﺮﻛﺰ ﺟﻮدارد ﻟﺮﺣﻼت اﻟﻔﻀﺎء اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﰲ ﺟﺮﻳﻨﺒﻴﻠﺖ ﺑﻮﻻﻳﺔ ﻣﺎرﻳﻼﻧﺪ " : ﺗﻴﺘﺎن ﻫﻮ ا ﻜﺎن اﻟﻮﺣﻴﺪ اﻵﺧﺮ ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ اﻟﺬي ﻳﺘﻤﺘﻊ ﺑﻄﻘﺲ ﻳﺸﺒﻪ ﻃﻘﺲ اﻷرض ﺑﻤﻌﻨـﻰ وﺟـﻮد ﺳﺤﺐ وأﻣﻄﺎر ﻋﲆ ﺳﻄﺤﻪ ." ﻗﺎم اﻟﻔﺮﻳﻖ ﺑﺮﺻـﺪ ﺗﻴﺘـﺎن ﰲ ﻧـﻮﻓﻤﱪ 2022 وﻳﻮﻟﻴﻮ 2023 ﺑﺎﺳﺘﺨﺪام ﺗﻠﺴﻜﻮب وﻳﺐ وأﺣﺪ اﻟﺘﻠﺴﻜﻮﺑ اﻷرﺿﻴ اﻟﺘﺎﺑ ﻌ ﺮاﺻﺪ دﺑﻠﻴﻮ . ﻟﻢ ﺗ . ﻛﻴﻚ . إم ﻈﻬﺮ ﻫﺬه اﻷرﺻﺎد وﺟﻮد ﺳﺤﺐ ﰲ ﺧﻄ ـﻮط اﻟﻌ ـﺮض اﻟﺸ ـﻤﺎﻟﻴﺔ ا ﺘﻮﺳ ـﻄﺔ واﻟﻌﺎﻟﻴﺔ ﻋﲆ ﺗﻴﺘﺎن ﻓﺤﺴﺐ وﻫﻮ ﻧ ﺼﻒ اﻟﻜﺮة اﻷرﺿﻴﺔ اﻟﺬي ﻳﺸﻬﺪ ﺣﺎﻟﻴ ﺎً ﻓﺼﻞ ا ﻟﺼﻴﻒ ﺑـﻞ أﻇﻬ ـﺮت أﻳﻀًــﺎ ارﺗﻔــﺎع ﺗﻠــﻚ اﻟﺴــﺤﺐ إﱃ ارﺗﻔﺎﻋﺎت أﻋـﲆ ﺑﻤـﺮور اﻟﻮﻗـﺖ . ﰲ ﺣـ أن اﻟﺪراﺳـﺎت اﻟﺴ ـﺎﺑﻘﺔ ﻗ ـﺪ رﺻـﺪت اﻟﺤﻤ ـﻞ اﻟﺤـﺮاري ﻟﻠﺴـﺤﺐ ﻋﻨـﺪ ﺧﻄـﻮط اﻟﻌـﺮض اﻟﺠﻨﻮﺑﻴﺔ، إﻻ أن ﻫﺬه ﻫـﻲ ا ـﺮة اﻷوﱃ اﻟﺘـﻲ اﻟﺠﻨﻮﺑﻴﺔ إﻻ أن ﻫـﺬه ﻫـﻲ ا ـﺮة اﻷوﱃ اﻟﺘـﻲ ﻳ ﺮﺻـﺪ ﻓﻴﻬـﺎ دﻟﻴـﻞ ﻋـﲆ ﻣﺜـﻞ ﻫـﺬا اﻟﺤﻤـﻞ اﻟﺤﺮاري ﰲ اﻟﺸﻤﺎل وﻫـﺬا ﻣﻬـﻢ ﻷن ﻣﻌﻈـﻢ ﺑﺤ ات وﺑﺤﺎر ﺗﻴﺘﺎن ﺗﻮﺟﺪ ﻪ ﰲ ﻧﺼﻔ اﻟﺸﻤﺎﱄ ﺣ ﻴﺚ ﻳُﻌـﺪ اﻟﺘﺒﺨـﺮ ﻣـﻦ اﻟﺒﺤـ ات ﻣﺼـﺪر اً ﺎً رﺋﻴﺴﻴ ﻣﺤﺘﻤﻼً ﻟﻠﻤﻴﺜﺎن وﺗﺸـﺒﻪ ﻣﺴـﺎﺣﺘﻬﺎ اﻹﺟﻤﺎﻟﻴـﺔ ﻣﺴـﺎﺣﺔ اﻟﺒﺤــ ات اﻟﻌﻈﻤـ ﻰ ﰲ ـــــ أﻣﺮﻳﻜﺎ اﻟﺸـﻤﺎﻟﻴﺔ . ﻋـﲆ اﻷرض ﺗﻤﺘـﺪ أدﻧـﻰ ﻃﺒﻘﺔ ﻣﻦ اﻟﻐـﻼف اﻟﺠـﻮي أو اﻟﱰوﺑﻮﺳـﻔ ﺣﺘﻰ ارﺗﻔﺎع ﺣﻮاﱄ 12 .اً ﻛﻴﻠﻮﻣﱰ أﻣــﺎ ﻋــﲆ ﺗﻴﺘ ـﺎن اﻟــﺬي ﺗﺴــﻤﺢ ﺟﺎذﺑﻴﺘــﻪ ا ﻨﺨﻔﻀﺔ ﺑﺘﻤﺪد ﻃﺒﻘﺎت اﻟﻐﻼف اﻟﺠﻮي ﻳﻤﺘﺪ اﻟﱰوﺑﻮﺳﻔ ﺣﺘﻰ ﺣﻮاﱄ 45 .اً ﻛﻴﻠـﻮﻣﱰ ﻟﻘـﺪ اﺳ ـﺘﺨﺪم ﺗﻠﺴــﻜﻮب وﻳــﺐ و ﻣﺮﺻ ـﺪ ﻛﻴــﻚ ــــــــ