Free Astronomy Magazine January-February 2025 ARABIC VERSION

Unusual jets of volatile gas from icy Centaur 29P byNASA/ESA/CSA Abigail Major ChristinePulliam nspired by the half-human, half- horse creatures that are part of AncientGreekmythology,the fieldofastronomyhasitsownkind ofcentaurs:distantobjectsorbit- ingtheSunbetweenJupiterand Neptune.NASA’sJamesWebbSpace Telescopehasmappedthegases spewingfromoneoftheseobjects, suggestingavariedcompositionand providingnewinsightsintothefor- mation and evolution of the solar system.Centaursareformertrans- Neptunian objects that have been movedinsideNeptune’sorbitbysub- tle gravitational influences of the planetsinthelastfewmillionyears, andmayeventuallybecomeshort- period comets. They are “hybrid” in the sense that they are in a transi- tional stage of their orbital evolu- tion:Manysharecharacteristicswith both trans-Neptunian objects (from the cold Kuiper Belt reservoir), and short-period comets, which are ob- jectshighlyalteredbyrepeatedclose passages around the Sun. JANUARY-FEBRUARY2025 I ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 10 ﻧﻔﺎﺛﺎت ﻏﺎز ﺔ ﻏ ﻋﺎد ﺔ ﻣﻦ اﻟﻘﻨﻄﻮراﻟ ـ ﺠﻠ ﺪ 29P ﻐأﺑ: ﻘﻠﻢ ﻴﻞ ﻣﻴﺠﻮر و ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ إﺳـﺘﻠﻬﻢ ﻋﻠﻢ اﻟﻔﻠﻚ ﻓ ﻜﺮة ا ﺨﻠﻮﻗﺎت اﻟﺘﻲ ﺗﺘﺄﻟﻒ ﻣﻦ ﻧﺼﻒ إﻧﺴـﺎن وﻧﺼـﻒ ﺣﺼـﺎن واﻟﺘﻲ ﺗﺸﻜﻞ ﺟﺰءاً ﻣﻦ اﻷﺳﺎﻃ اﻟﻴﻮﻧﺎﻧﻴـﺔ اﻟﻘﺪﻳﻤﺔ ﻟﻴﻄﻠﻘﻬـﺎ ﻋـﲆ ﻧـﻮع ﻏﺮﻳـﺐ ﻣـﻦ اﻷﺟﺮام اﻟﻔﻀﺎﺋﻴﺔ اﻟﺘﻲ ﺗﺪور ﺣﻮل اﻟﺸـﻤﺲ ﺑ ﻛـﻮﻛﺒﻲ ا ﺸـﱰي وﻧﺒﺘـﻮن وﻗـﺪ ﻗـﺎم ﺗﻠﺴﻜﻮب ﺟـﻴﻤﺲ وﻳـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ﺑﺮﺳﻢ ﺧﺮﻳﻄﺔ ﻟﻠﻐـﺎزات اﻟﺘـﻲ ـــ ﺗﻨﻄﻠﻖ ﻣﻦ أﺣﺪ ﻫﺬه اﻷﺟﺮام ﻣﻤـﺎ ﻳﺸـ إﱃ ﺗﻨﻮع ﺗﺮﻛﻴﺒﻬﺎ وﺗـﻮﻓ رؤ ى ﺟﺪﻳـﺪة ﺣـﻮل ﺗﻜﻮﻳﻦ وﺗﻄﻮر اﻟﻨﻈﺎم اﻟﺸﻤﴘ . اﻟﻘﻨﻄﻮر ات ﻫﻲ أﺟ ﺮام ﻛﺎﻧﺖ ﺳﺎﺑﻘًﺎ ﺧﺎرج ﻣﺪار ﻧﺒﺘـﻮن وﻗﺪ ﺗﻢ ﺗﺤﺮﻳﻜﻬﺎ ودﻓﻌﻬـﺎ إﱃ داﺧـﻞ ﻣـﺪار ﻧﺒﺘﻮن ﺑﻔﻌﻞ ﺗـﺄﺛ ات اﻟﺠﺎذﺑﻴـﺔ اﻟﺒﺴـﻴﻄﺔ ﻟﻠﻜﻮاﻛـﺐ ﺧـﻼل ﻣﻼﻳــ اﻟﺴـﻨ اﻟﻘﻠﻴﻠـﺔ ا ﺎﺿﻴﺔ وﻗﺪ ﺗﺘﺤﻮل ﰲ ا ﻟﻨﻬﺎﻳـﺔ إﱃ ﻣـﺬﻧﺒﺎت ـــ ﻗﺼ ة اﻟﺪورة . ﺗﺼﻨﻒ اﻟﻘﻨﻄﻮرات ﻋﲆ أ ﻧﻬﺎ أﺟﺮام " " ﻫﺠﻴﻨـﺔ ﺑﻤﻌﻨـﻰ أﻧﻬـﺎ ﰲ ﻣﺮﺣﻠـﺔ اﻧﺘﻘﺎﻟﻴﺔ ﻣﻦ ﺗﻄﻮر ا ﻫﺎ : يﺪار ﻓﻜﺜ ﻣﻨﻬـﺎ ﻳﺸﱰك ﰲ ﺧﺼﺎﺋﺺ ﻣﻊ ﻛـﻞ ﻣـﻦ اﻷﺟـﺮام ﺧﺎرج ﻣﺪار ﻧﺒﺘﻮن ) ﻣﻦ ﺧﺰان ﺣﺰام ﻛـﺎﻳﱪ اﻟﺒﺎرد ( وا ﺬﻧﺒﺎت ﻗﺼـ ة اﻟـﺪورة أﺟﺴـﺎم ﻣﺘﻐ ة ﻟﻠﻐﺎﻳﺔ ﺑ ﺴﺒﺐ اﻻﻗﱰاﺑـﺎت ا ﺘﻜـ ﺮرة ﻣﻦ ﻗﺮص اﻟﺸﻤ . ﺲ ا ﺘﻮﻫﺞ - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 5