Free Astronomy Magazine January-February 2023 ARABIC VERSION

L the intracellular matrix. The information stored in DNA is only accessible because it can be uncoiled, read, repaired, and recombined in the fluid chemical environment within the water-filled cell. Liquid water, by the fact that it is not frozen into a crystalline lattice of ice, also provides the medium within which all of these small, biologically rele- vant molecules can come to be in close proximity and com- bine to make larger, biologi- cally relevant molecules. This is why the several recent dis- coveries of salty subsurface pockets of liquid water on Mars are specifically exciting to astrobiologists – simply ex- isting in a liquid form means chemical processes can be oc- curring that are otherwise im- possible in solid ice, even if the salt content and still ex- tremely cold temperatures significantly impact the rates and di- rections of those reactions. The book describing all we currently know about the chemistry of life and the transition from simple mol- ecules to the simplest organisms is dwarfed by the many volumes that could be written about those things we currently do not know about that same transition. It may come to pass that the books describing the things “we do not know that we do not know” may eventually be larger still. With all that said about the chemistry of life on Earth, we return to the issue of simple organic molecules on the sur- face of an ancient, frozen, and barren planet unpro- tected for billions of years from solar radiation of all wavelengths. The samples from Wildcat Ridge are unique among all previous finds on Mars because of the high concentration of organics detected by the SHERLOC (Scanning Habitable Environments with eft, this sealed titanium sample tube contains Perseverance’s first cored sample of Mars rock. The rover’s Sampling and Caching System Camera (known as CacheCam) captured this image. Right, Perseverance’s first cored-rock sample of Mars rock is seen inside its titanium container tube in this image taken by the CacheCam. [NASA/JPL-Caltech] ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٩ إن ا ﻌﻠﻮﻣـﺎت ا ﺨﺰﻧـﺔ ﰲ اﻟﺤﻤــﺾ اﻟﻨــﻮوي ﻫ ـﻲ ﻓﻘ ـﻂ اﻟﺘ ـﻲ ﻳﻤﻜ ـﻦ اﻟﻮﺻـﻮل اﻟﻴﻬـﺎ ﻷﻧـﻪ ﻳﻤﻜـﻦ ﻓﻜﻬـﺎ وﻗﺮاءﺗﻬـــﺎ وإﺻ ــﻼﺣﻬﺎ وإﻋ ــﺎدة ﺗﺠﻤﻴﻌﻬــﺎ ﰲ اﻟﺒﻴﺌــﺔ اﻟﻜﻴﻤﻴﺎﺋﻴــﺔ اﻟﺴﺎﺋﻠﺔ داﺧﻞ اﻟﺨﻠﻴﺔ ا ﻠﻴﺌـﺔ ﺑﺎ ـﺎء . ا ﺎء اﻟﺴـﺎﺋﻞ ، ﺑﺤﻘﻴﻘـﺔ أﻧـﻪ ﻻ ﻳـﺘﻢ ﺗﺠﻤﻴﺪه ﰲ ﺷﺒﻜﺔ ﺑﻠﻮرﻳﺔ ﻣﻦ اﻟﺠﻠﻴـﺪ ﻳﻮﻓﺮ أﻳﻀً ﺎ اﻟﻮﺳـﻂ اﻟـﺬي ﻳﻤﻜـﻦ أن ﺗﻜـﻮن ﻓﻴــﻪ ﻛ ـﻞ ﻫ ـﺬه اﻟﺠﺰﻳﺌــﺎت اﻟﺼﻐ ة ذات اﻟﺼﻠﺔ ﺑﻴﻮﻟﻮﺟﻴًﺎ ﻗﺮﻳﺒﺔ ﺟﺪًا وﺗﺘﺤﺪ ﻟﺘﻜـﻮﻳﻦ ﺟﺰﻳﺌـﺎت أﻛـﱪ وذات ﺻﻠﺔ ﺑﻴﻮﻟﻮﺟﻴًﺎ ﻫﺬا ﻫﻮ اﻟﺴﺒﺐ ﰲ أن اﻻﻛﺘﺸﺎﻓﺎت اﻟﻌﺪﻳـﺪة اﻟﺤﺪﻳﺜـﺔ ﻟﺠﻴ ـﻮب ا ﻴ ـﺎه اﻟﺴ ـﺎﺋﻠﺔ اﻟﺠﻮﻓﻴ ـﺔ ا ﺎﻟﺤﺔ ﻋـﲆ ﺳـﻄﺢ ا ـﺮﻳﺦ ﻣﺜـ ة ﺑﺸــﻜﻞ ﺧــﺎص ﻟﻌﻠﻤــﺎء اﻷﺣﻴــﺎء اﻟﻔﻠﻜﻴــﺔ ا ﻮﺟــﻮدة ﺑﺒﺴــﺎﻃﺔ ﰲ ﺷــﻜﻞ ﺳــﺎﺋﻞ ﻳﻌﻨــﻲ أن اﻟﻌﻤﻠﻴــﺎت اﻟﻜﻴﻤﻴﺎﺋﻴــﺔ ﻳﻤﻜــﻦ أن ﺗﺤــﺪث و ﻣــﻦ ا ﺴــﺘﺤﻴﻞ ﺣ ـﺪو ﺛﻬﺎ ﰲ اﻟﺠﻠﻴــﺪ اﻟﺼ ـﻠﺐ ﺣﺘــﻰ ﻟــﻮ ﻛــﺎن ﻳ ﺤﺘ ـﻮى ا ﻠــﺢ وﻻ ﻳــﺰال ﺷــﺪ ﻳﺪ اﻟــﱪودة ﺗــﺆﺛﺮ درﺟــﺎت اﻟﺤــﺮارة ﺑﺸــﻜﻞ ﺑﺸﻜﻞ ﻛﺒ ﻋﲆ ﻣﻌﺪﻻت واﺗﺠﺎﻫـﺎت ﺗﻠﻚ اﻟﺘﻔﺎﻋﻼ .ت اﻟﻜﺘﺎب اﻟـﺬي ﻳﺼـﻒ ﻛﻞ ﻣـﺎ ﻧﻌﺮﻓـﻪ ﺣﺎﻟﻴًـﺎ ﻋـﻦ ﻛﻴﻤﻴـﺎء اﻟﺤﻴــﺎة واﻻﻧﺘﻘ ـﺎل ﻣــﻦ اﻟﺠﺰﻳﺌــﺎت اﻟﺒﺴﻴﻄﺔ إﱃ أﺑﺴﻂ اﻟﻜﺎﺋﻨﺎت ﻳﺘﻀﺎءل أﻣﺎم ا ﺠﻠﺪات اﻟﻌﺪﻳـﺪة اﻟﺘـﻲ ﻳﻤﻜـﻦ ﻛﺘﺎﺑﺘﻬﺎ ﻋﻦ ﻫﺬه اﻷﺷـﻴﺎء . ﻻ ﻧﻌـﺮف ﺣﺎﻟﻴًﺎ ﻋﻦ ﻧﻔﺲ اﻻﻧﺘﻘﺎل . ﻗﺪ ﻳﺤـﺪث أن اﻟﻜﺘـﺐ اﻟﺘـﻲ ﺗﺼـﻒ اﻷﺷـﻴﺎء ﻻ " ﻧﻌﺮف أﻧﻨـﺎ ﻻ ﻧﻌـﺮف " ﻗـﺪ ﺗﻜـﻮن ﰲ اﻟﻨﻬﺎﻳﺔ أﻛﱪ ﻣﻦ ذﻟﻚ . ﻣﻊ ﻛﻞ ﻣﺎ ﻗﻴﻞ ﻋﻦ ﻛﻴﻤﻴﺎء اﻟﺤﻴﺎة ﻋﲆ اﻷ رض ، ﻧﻌﻮد إﱃ ﻣﺴــﺄﻟﺔ اﻟﺠﺰﻳﺌــﺎت اﻟﻌﻀــﻮﻳﺔ اﻟﺒﺴﻴﻄﺔ ﻋﲆ ﺳـﻄﺢ ﻛﻮﻛـﺐ ﻗـﺪﻳﻢ وﻣﺠﻤﺪ وﻗﺎﺣﻞ وﻏ ﻣﺤﻤﻲ ﻠﻴﺎرات اﻟﺴﻨ ﻣـﻦ اﻹﺷـﻌﺎع اﻟﺼـﺎدر ﻣـﻦ اﻟﺸﻤﺲ ﻋﲆ ﺟﻤﻴﻊ اﻷﻃﻮال ا ﻮﺟﻴﺔ . ﺗﻌﺘﱪ اﻟﻌﻴﻨﺎت ﻣﻦ ﺻﺨﺮة ) واﻳﻠﺪ ﻛﺎت ( رﻳﺪج ﻓﺮﻳﺪة ﻣﻦ ﻧﻮﻋﻬﺎ ﺑـ ﺟﻤﻴـﻊ اﻻﻛﺘﺸـﺎﻓﺎت اﻟﺴـﺎﺑﻘﺔ ﻋـﲆ ا ـﺮﻳﺦ ﺑﺴﺒﺐ اﻟﱰﻛ ﻴﺰ اﻟﻌﺎﱄ ﻟﻠﻤﻮاد اﻟﻌﻀﻮﻳﺔ اﻟﺘــﻲ اﻛﺘﺸــﻔﻬﺎ ﺟﻬــﺎز ﺷــ ﻟﻮك ﺑﺎﺳﺨﺪام ﻣﻄﻴﺎف راﻣﺎن ﻋـﲆ ﻣـﺘﻦ ا ﺴﺒﺎر ا ﺘﺠﻮل ﺑ ﺳﻴﻔ اﻧ .ﺲ ــــــــــــــــــــــﺔ أﻧﺒﻮ اﻟﻌ ﻨــــــــــــــــــــــﺎت رﻗـــــــــــــــــــــــﻢ ٢٦٦ اﺳــــﺘﺨﺪﻣﺖ ـﻟــــ ﻤﻊ اﻟﻌ ﻨــــﺔ اﻷوﻟـــــﻰ ﻣـــــــــــــﻦ ﺻـــــــــــــﺨﻮراﻟﻤـــــــــــــﺮ ﺦ ﺑﻮاﺳـــــــــــــﻄﺔ اﻟﻤﺴـــــ ﺎر اﻟﻤﺘﺠـــــﻮل ﺑ ﺳـــــ ﻔ اﻧﺲ ﺴــــــــــــــــــﺎﻋﺪ اﻟـــــــــــــــــــﺮﻗﻢ اﻟﺘﺴﻠﺴـــــــــــــــــــﻠﻲ ــــــــﺎﻟﻠ ر اﻟﻤﺤﻔــــــــﻮر اﻟﻌﻠﻤــــــــﺎء ﻋﻠــــــــﻰ ﺗﺤﺪ ﺪ اﻷﻧﺎﺑ ﺐ وﻣﺤﺘﻮ ﺎﺗﻬﺎ . أﻧﺒﻮب ﻋ ﻨﺔ اﻟﺘ ﺘﺎﻧﻴﻮم اﻟﻤﺨﺘﻮم ( ﺴﺎر ) ﻳﺤﺘﻮي ﻋﻠﻰ أول ﻋ ﻨﺔ ﻣﺤﻔﻮر ة ﻣﻦﺻﺨﻮر اﻟﻤﺮ ﺦ ﺑﻮاﺳﻄﺔ اﻟﻤﺴ ﺎر اﻟﻤﺘﺠﻮل ﺑ ﺳ ﻔ اﻧﺲ . اﻟﺘﻘﻄﺖ ﺎﻣ ا ﻧﻈﺎم أﺧﺬ اﻟﻌ ﻨﺎت واﻟﺘﺨﺰ ﻦ اﻟﻤﺆﻗﺖ ) اﻟﻤﻌﺮوﻓﺔ ﺎﺳﻢ ﺎش ﺎم ( ﻫﺬﻩ اﻟﺼﻮرة اﻟ( ﻤ. ) ﻌ ﻨﺔ داﺧﻞ أﻧﺒﻮبﺣﺎو ﺔ اﻟﺘ ﺘﺎﻧﻴﻮم ﻳﻨﺎﻳﺮ ﻓ اﻳﺮ 2023