Free Astronomy Magazine November-December 2023 ARABIC VERSION

bility and varied chemistry. On Earth, they are most often found in bitumen, a thick, viscous form of pe- troleum, but may be most com- monly associated with the incomplete combustion of organic materials – from raging forest fires to the burning kindling in the fam- ily hearth to the match that can ini- tiate both. They are generally stable molecules and result from reactive carbon atoms and hydrocarbon fragments trying to combine and rearrange into geometries that are stable under harsh conditions, be those fires on Earth or the high-ul- traviolet (UV) conditions around new and old stars. In terms of the detection of any molecules, astronomers and astro- chemists benefit greatly from the general absence of very large mole- cules in space. Just as a conversation is easier with only one person in a room answering your question than with 1,000 people in that same room simultaneously providing dif- ferent answers to that same ques- tion, small molecules absorb and emit photons of a very limited set of energies that are easier to detect when the quantities and variety of other molecules is limited. These en- ergies become the vibrational and electronic spectra from which we obtain what are referred to as spec- tral “fingerprints” – features in these spectra that, with high confi- dence, correspond to very specific arrangements of atoms. Not only is water very different from carbon dioxide or methane, but even dif- ferent arrangements of the same atoms, referred to chemically as structural isomers , produce unique spectra. These fingerprints also seem to hold across space and time. When a mo- lecular spectrum is recorded from a sample brought back from a mole- cule on Ryugu or, eventually, some sample return mission from Mars, ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 11 ﺣﺎﻟﺔ ﻣﺤﺪدة ﻛﻴﻤﻴﺎﺋﻴًﺎ ﻣـﻦ ﻫـﺬه ﺗﺘﺸـﺎرك اﻟﺠﺰﻳﺌﺎت اﻹﻟﻜﱰوﻧﺎت ﺑ ﺣﻠﻘﺎت اﻟﻜﺮﺑﻮن اﻟﺨﺎﺻﺔ ﺑﻬﺎ ﺑﻄﺮﻳﻘﺔ ﺗﺰﻳﺪ ﻣﻦ اﺳـﺘﻘﺮارﻫﺎ وﺗﻨﻮﻋﻬﺎ اﻟﻜﻴﻤﻴﺎﺋﻲ . ﻳﺘﻢ اﻟﻌﺜﻮر ﻋﲆ اﻷرض ﻋﻠﻴﻬﺎ ﻏﺎﻟﺒﺎً ﰲ اﻟﺒﻴﺘﻮﻣ وﻫﻮ ﺷﻜﻞ ﺳـﻤﻴﻚ وﻟﺰج ﻣﻦ اﻟﻨﻔﻂ وﻟﻜﻨﻬﺎ ﻗﺪ ﺗـﺮﺗﺒﻂ ﺑﺸـﻜﻞ ﺷ ـﺎﺋﻊ ﺑ ـﺎﻻﺣﱰاق ﻏ ـ اﻟﻜﺎﻣ ـﻞ ﻟﻠﻤ ـﻮاد اﻟﻌﻀﻮﻳﺔ ﺑﺪء اً ﻣﻦ ﺣﺮاﺋﻖ اﻟﻐﺎﺑﺎت ا ﺴﺘﻌﺮة إﱃ إﺷـﻌﺎل اﻟﻨـﺎر ﰲ ﻣﻮﻗـﺪ اﻷ ﴎة إﱃ ﻋـﻮد اﻟﺜﻘﺎب اﻟﺬي ﻳﻤﻜـﻦ ـ اﻟـ ﴩوع ﰲ ﻛﻠﻴﻬﻤـﺎ وﻫﻲ ﺑﺸﻜﻞ ﻋﺎم ﺟﺰﻳﺌﺎت ﻣﺴﺘﻘﺮة وﺗﻨـﺘﺞ ﻣ ـﻦ ذرات اﻟﻜﺮﺑــﻮن اﻟﺘﻔﺎﻋﻠﻴ ـﺔ وﺷــﻈﺎﻳﺎ اﻟﻬﻴﺪروﻛﺮﺑﻮن اﻟﺘﻲ ﺗﺤﺎول اﻻﻧﺪﻣﺎج وإﻋﺎدة ﺗﺮﺗﻴﺒﻬ ﺎ ﰲ أﺷﻜﺎل ﻫﻨﺪ ﺳﻴﺔ ﻣﺴﺘﻘﺮة ﰲ ﻇـﻞ اﻟﻈﺮوف اﻟﻘﺎﺳﻴﺔ ﺳﻮاء ﻛﺎﻧﺖ ﺗﻠﻚ اﻟﺤﺮاﺋـﻖ ﻋــﲆ اﻷرض أو ﻇــﺮوف اﻷﺷــﻌﺔ ﻓــﻮق اﻟﺒﻨﻔﺴﺠﻴﺔ اﻟﻌﺎ ﻟﻴﺔ ﺣﻮل اﻟﻨﺠـﻮم اﻟﺠﺪﻳـﺪة واﻟﻘﺪﻳﻤــﺔ وﻓﻴﻤــﺎ ﻳﺘﻌﻠــﻖ ﺑﺎﻛﺘﺸــﺎف أي ﺟﺰﻳﺌﺎت، ﻳﺴﺘﻔﻴﺪ ﻋﻠﻤﺎء اﻟﻔﻠـﻚ واﻟﻜﻴﻤﻴـﺎء اﻟﻔﻠﻜﻴﺔ ﺑﺸـﻜﻞ ﻛﺒـ ﻣـﻦ اﻟﻐﻴـﺎب اﻟﻌـﺎم ﺟﺰﻳﺌﺎت، ﻳﺴﺘﻔﻴﺪ ﻋﻠﻤﺎء اﻟﻔﻠـﻚ واﻟﻜﻴﻤﻴـﺎء اﻟﻔﻠﻜﻴﺔ ﺑﺸـﻜﻞ ﻛﺒـ ﻣـﻦ اﻟﻐﻴـﺎب اﻟﻌـﺎم ﻟﻠﺠﺰﻳﺌﺎت اﻟﻜﺒ ة ﺟـﺪًا ﰲ اﻟﻔﻀـﺎء . ﻣﺜﻠﻤـﺎ ﺗﻜﻮن ا ﺤﺎدﺛﺔ ﻣﻊ ﺷﺨﺺ واﺣـﺪ ﻓﻘـﻂ ﰲ ﻏﺮﻓﺔ ﻟﻺﺟﺎﺑﺔ ﻋﲆ ﺳﺆاﻟﻚ أﺳﻬﻞ ﻣﻦ إﺟـﺮاء ﻣﺤﺎدﺛﺔ ﻣﻊ 1000 ﺷﺨﺺ ﰲ ﻧﻔﺲ اﻟﻐﺮﻓﺔ ﻳﻘﺪﻣﻮن ﰲ ﻧﻔﺲ اﻟﻮ ﻗﺖ إﺟﺎﺑـﺎت ﻣﺨﺘﻠﻔـﺔ ﻋﲆ ﻧﻔﺲ اﻟﺴﺆال ﻓﺈن اﻟﺠﺰﻳﺌﺎت اﻟﺼـﻐ ة ﺗﻤﺘﺺ وﺗ ﺼـﺪر ﻓﻮﺗﻮﻧـﺎت ﻣـﻦ ﻣﺠﻤﻮﻋـﺔ ﻣﺤﺪودة ﺟﺪ ﻣـﻦ اً اﻟﻄﺎﻗـﺎت اﻟﺘـﻲ ﻳﺴـﻬﻞ اﻟﺤﺼﻮل ﻋﻠﻴﻬﺎ اﻛﺘﺸﺎف ﻣﺘﻰ ﺗﻜﻮن ﻛﻤﻴﺎت وﺗﻨﻮع اﻟﺠﺰﻳﺌﺎت اﻷﺧﺮى ﻣﺤﺪودة وﺗﺘﺤــﻮل ﻫــﺬه اﻟﻄﺎﻗــﺎت إﱃ اﻷﻃﻴــﺎف اﻻﻫﺘﺰازﻳﺔ واﻹﻟﻜﱰوﻧﻴﺔ اﻟﺘﻲ ﻧﺤﺼﻞ ﻣﻨﻬـﺎ ﻋـﲆ ﻣـﺎ ﻳﺸـ ﺎر إﻟﻴـﻪ ﺑﺎﺳـﻢ اﻟ" ﺒﺼـﻤﺎت " اﻟﻄﻴﻔﻴﺔ وﻫـﻲ ﺳـﻤﺎت ﰲ ﻫـﺬه اﻷﻃﻴـﺎف ﺗﺘﻮاﻓﻖ، ﺑﺜﻘﺔ ﻋﺎﻟﻴﺔ ﻣـﻊ ﺗﺮﺗﻴﺒـﺎت ﻣﺤـﺪدة و ﺟﺪًا ﻟﻠﺬرات ﻟﻴﺲ ا ﺎء ﻣﺨﺘﻠﻔًﺎ ﺗﻤﺎﻣـ ﺎً ﻋـﻦ ﺛﺎﻧﻲ أﻛﺴﻴﺪ اﻟﻜﺮﺑﻮن أو ا ﻴﺜﺎن ﻓﺤﺴﺐ، ﺑﻞ ﺛﺎﻧ ﻲ أﻛﺴﻴﺪ اﻟﻜﺮﺑﻮن أو ا ﻴﺜﺎن ﻓﺤﺴﺐ ﺑـﻞ ﺣﺘﻰ اﻟﱰﺗﻴ ﺒـﺎت ا ﺨﺘﻠﻔـﺔ ﻟـﻨﻔﺲ اﻟـﺬرات واﻟﺘﻲ ﻳﺸﺎر إﻟﻴﻬﺎ ﻛﻴﻤ ﻴﺎﺋﻴًﺎ ﺑﺎﺳﻢ اﻷﻳﺰوﻣﺮات اﻟﻬﻴﻜﻠﻴﺔ ﺗﻨﺘﺞ أﻃﻴﺎﻓًﺎ ﻓﺮﻳـﺪة ﻣـﻦ ﻧﻮﻋﻬـﺎ . ﻳﺒﺪو أﻳﻀًﺎ أن اﻟ ﺒﺼﻤﺎ ت ﻫﺬه ﻣﺘﻤﺎﺳﻜﺔ ﻋﱪ ا ﻜﺎن واﻟﺰﻣﺎن ﻋﻨﺪﻣﺎ ﻳﺘﻢ ﺗﺴﺠﻴﻞ اﻟﻄﻴـﻒ اﻟﺠﺰﻳﺌﻲ ﻣﻦ ﻋﻴﻨﺔ ﺗﻢ إﺣﻀﺎرﻫﺎ ﻣﻦ ﺟﺰيء ﻋﲆ اﻟﻜﻮﻳﻜﺐ وأ ( رﻳﻮﺟﻮ ) ﺑﻌﺾ ﻣﻬﻤـ ﺎت ا ﺟﻠﺐ ﺎت ﻟﻌﻴﻨ ﻣﻦ ا ﺮﻳﺦ . ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 3 ـﺔ اﻟــﺠﺎﻣﻌ ﺔ ﻟ ﻠـﻲﻛ ﺘﻠــﺮﻋﻠـﻰاﻟ ﺴـﺎر اﻟﻄﺎﻟ ﻓﻴــــــــــــ ا وﻃﺎﻟــــــــــــﺐ واﻟ وﻓ ﺴــــــــــــﻮرﺟــــــــــــﻮاﻛ ــــﺪارﻓــــﺎدﻛﻲﻫــــﻢﺟــــﺰء ــــﺎ ﻛ اﻟﺪراﺳــــﺎتاﻟﻌﻠ ﻣــﻦ ﻓﺮ ـــﻖدوﻟـــﻲاﻛﺘﺸـــﻒﺟﺰ ﺌـــﺎتﻋﻀـــﻮ ﺔ ﻣﻌﻘـﺪةﻓـﻲﻣﺠـﺮة ﺗ ﻌـﺪ أﻛـ ﻣـﻦ 12 ـﺎر ﻣﻠ ﺳــﻨﺔﺿــﻮﺋ ﺔﻋــﻦ اﻷرض وﻫــﻲأ ﻌــﺪ ﻣﺠـــﺮة ﻣﻌﺮوﻓﺔ اﻵن ﺑﻬﺬﻩ اﻟـﺠﺰ ﺌ . ﺎت