Free Astronomy Magazine July-August 2025 ARABIC VERSION

dance of carbon dioxide (CO 2 ), while the signals of ammonia (NH 3 ) and carbonmonoxide(CO)wereabsent, a scenario in good agreement with the hycean model developed by Madhusudhan’s team. It is in these same spectra that the researchers believed they recognized for the firsttimethepossibletracesofDMS, or alternatively DMDS (dimethyl disulfide,CH 3 S 2 CH 3 ),anotherbiosig- nature,superimposabletothefirst intermsofspectralproperties.How- ever,itwasafeeblesignalwithlittle statistical relevance that could have beengeneratedbyrandomfluctua- tions,noise,ormeasurementerrors. The2024observations After using Webb for just over ten hours in 2023, Madhusudhan’s team was given an additional period of nearly six hours to obtain more transmissionspectraofK2-18btran- siting in front of the disk of its star. The new observations took place be- tween April 25 and 26, 2024, usingon that occasion the MIRI spectro- graph (Mid-Infrared Instrument, op- erating in the 5-28 microns range). Looking for biosignatures with a dif- ferent instrument from the previous ones, in an infrared band adjacent and complementary to that covered by the other two spectrographs, would have given credibility to the DMS (or DMDS) signal if it had man- ifested itself again. And “the signal came through loud and clear,” com- mented Madhusudhan, who added: “This is an independent line of evi- dence, using a different instrument in a different wavelength range, where there is no overlap with pre- vious observations.” The new investigation would seem to have strengthened the hypothe- sis of the presence of life on K2-18 b,providedthatalltheassumptions thatledresearcherstointerpret those traces, in truth ethereal, as biosignatures are considered valid. Among those assumptions, there arequiteafewscenariosproposed in the form of scientific articles by Madhusudhan himself, which makes the conclusions he and his team reach somewhat self-referential. JULY-AUGUST2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 9 ﺗﻈﻬـﺮ اﻟﺘﻘﻄﺘﻬــﺎ أداة اﻷﺷـﻌﺔ ﺗﺤــﺖ اﻟــ ــﻒ اﻹرﺳــﺎل اﻟــ ﻫﻨــﺎ ﺑ ﺎﻧـﺎتﻃ ـ ﻤﺮاء اﻟﻤﺘﻮﺳـﻄﺔ ( ﻣــ ي) ـﺐ اﻟﻔﻀــﺎﺋﻲ ﺗﻠﺴـ ﻮبﺟــ ﻤﺲو ﻋﻠـﻰﻣــ ﻓﺤﺼــﺖ اﻟﻐـﻼف اﻟــ واﻟـ ـ ﺠﻮي ﻟﻠ ﻮﻛـﺐ اﻟ ﻨ ﻤــﻲ اﻟﻌــﺎﺑﺮ K2-18b . ﺗﻈﻬــــﺮ ــــﻞ ﻧﻘﻄــــﺔ ﺑ ﺎﻧــــﺎت ﺑ ﻨﻤــــﺎ ــــﺎسﻓــــﻲ أﺧﻄــــﺎء اﻟﻘ ـ ﻈﻬــــﺮاﻟــــ ــــﻒ اﻟ ﻠــــﻲ ﺨﻂ اﻷزرق اﻟﻄ اﻷﻣﺜـﻞ . ــﺎة دﻓﻌـﺖ ﻓﺮ ـﻖﻣﺎدوﺳـﻮدان إﻟـﻰ اﻹﻋــﻼن ﻋـﻦ اﺣﺘﻤـﺎل وﺟـﻮد ﺣ ﻫـﺬﻩ ﻫـﻲ اﻟﻘ ﺎﺳـﺎت اﻟـ ﻋﻠﻰ اﻟ ﻮﻛﺐ K2-18b . [N. Madhusudhan et al., 2024] ﺗﻈﻬﺮ اﻟﺒ ﺎﻧﺎت اﻟ ﻄ ﻔ ﺔ ﺑﻮاﺳﻄﺔ ـﺐ اﻟﻔﻀـﺎﺋﻲ ﺗﻠﺴ ﻮبﺟ ﻤﺲو ﻟﻠ ﻮﻛـﺐ اﻟ ﻨ ﻤـﻲ K2-18b اﻧـﮫ ﺘﻮاﻓﻖ ﻣﻊ ﺳﻠﺴﻠﺔ ﻣﻦ ﺟﺰ ﺌﺎت اﻟﻀﻮء ﻣﺜﻞ اﻟﻤ ﺜﺎن وﺛﺎﻧﻲ أﻛﺴ ﺪ اﻟﻜﺮ ـﻮن، إﻟـﻰﺟﺎﻧـﺐ ﺛﻨـﺎﺋﻲﻣ ﺜﻴـﻞ اﻟﻜ ﺘ ﺪ و ـﺪ ﺛﻨﺎﺋﻲ ﻣ ﺜﻴﻞ ﺛﻨﺎﺋﻲ اﻟﻜ ﺘ إﻻ أن " ـﺔ أﻫﻤ "3- ﺳـ ﻐﻤﺎ ﻟـﻢ ﺗُﻜﺘﺸـﻒ إﻻ ﻌـﺪ اﺳـﺘ ﻌﺎد ﻤﻴـﻊ ـــﺪأ ﻣـــﻦ ـــﺔ ﺗ ﻗـــﺪ ﺗُﻈﻬـــﺮﺧﺎﺻـــ ﺔ اﻣﺘﺼـــﺎصﻗﻮ أﻧـــﻮاع اﻟﻐـــﺎزات اﻷﺧـــﺮى اﻟﻤﺤﺘﻤﻠـــﺔ اﻟـــ 9 ﻣ ﻜـــﺮون ﻣـــﻦ اﻟﺘﺤﻠﻴــــﻞ . ــــﺎرأ ﻀًــــﺎ ﻫﻨــــﺎكﺳــــ ﻨﺎر ﻮﻫﺎت أﺧــــﺮىﻗﺎ ﻠــــﺔ ﻟﻠﺘﻄﺒﻴــــﻖ ﻘــــﻮة ﻳﺠــــﺐ أﺧــــﺬﻫﺎ ﻓــــﻲ اﻻﻋﺘ . ﻓــــﻲ اﻟﺴـ ﺎﻗﺎ ـﺔ ﻳ ت اﻟﻌﻠﻤ ﺤـﺪد ﺳـ ﻐﻤﺎ ) σ ( ـﺎﻳﻦ أو ﺗﺸـﺘﺖ ﻧﻘـﺎط اﻟﺒ ﺗ ﺎﻧـﺎتﺣـﻮل اﻟﻤﺘﻮﺳـﻂ . ﺸـ ارﻔــﺎع ﻣﺴـــﺘﻮ ىﺳـــ ﻐﻤﺎ إﻟـــﻰ ﺛﻘـــﺔ أﻛـــ ﻓـــﻲ اﻟﻨﺘﻴﺠـــﺔ ـــﻮن ﻫﻨـــﺎك أي أﻧـــﮫ ﻣـــﻦ ﻏـــ اﻟﻤـــﺮﺟﺢ أن ﻳ ﻣﻤـــﺎ ﻌـــ اﺣﺘﻤﺎل ﻟﻮﺟﻮد ﺿﻮ . ﺿﺎء 3- ﺳ ﻐﻤﺎ ﻗ ﻤﺔ ﻣﻮاﺗ ﺔ ﻟﻠﻐﺎ ﺔ ﻟﻜﻨﻬﺎ ﻻ ﺗُﺜ ﺖﺻﺤﺔ اﻻﻛﺘﺸﺎف . إن ﻏﻴــﺎب إﺷــﺎ رات اﻷﻣﻮﻧﻴــﺎ وأول أﻛﺴــﻴﺪ اﻟﻜﺮﺑﻮن وﻫ ﻮ أﻣـﺮ ﻻﻓـﺖ ﻟﻠﻨﻈـﺮ وﻳﺴـﺘﺤﻖ اﻟﺪراﺳﺔ ﻳﺘﻮاﻓﻖ ﺗﻤﺎﻣًﺎ ﻣﻊ ﻧﻤـﻮذج ﻫﻴﺸـﻴﺎن اﻟﺬي ﻃﻮره ﻓﺮﻳﻖ ﻣﺎدوﺳﻮدان . ﻋﻨﺪ ﻓﺤﺺ اﻷﻃﻴﺎف ﻧﻔﺴﻬﺎ اﻋﺘﻘﺪ اﻟﺒﺎﺣﺜﻮن أﻧﻬﻢ ﺗﻌﺮﻓﻮا ﻷول ﻣﺮة ﻋـﲆ اﻵﺛـﺎر ا ﺤ ﺘﻤﻠـﺔ ﻟﺜﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴـﺪ أو ﺑـﺪﻻً ﻣـﻦ ﺛﻨـﺎﺋﻲ ﻣﻴﺜﻴﻞ ﺛﻨﺎ ﺋﻲ اﻟﻜﱪﻳﺪ وﻫﻮ ﺳﻤﺔ ﺣﻴﻮﻳﺔ أﺧﺮى ﻳﻤﻜﻦ ﺗﻄﺒﻴﻘﻬﺎ ﻋﲆ اﻟﺴﻤﺔ اﻷوﱃ ﻣـﻦ ﺣﻴـﺚ اﻟﺨﺼﺎﺋﺺ اﻟﻄﻴﻔﻴﺔ . وﻣﻊ ذﻟﻚ ﻛﺎﻧﺖ ﻫﺬه إﺷﺎرة آﻣﻨﺔ ذات أﻫﻤﻴﺔ إﺣﺼﺎﺋﻴﺔ ﺿﺌﻴﻠﺔ واﻟﺘﻲ ﻛﺎن ﻣـﻦ ا ﻤﻜـﻦ أن ﺗﻨﺸﺄ ﻋﻦ اﻟﺘﻘﻠﺒﺎت اﻟﻌﺸﻮاﺋﻴﺔ أو اﻟﻀﻮﺿﺎء أو أﺧﻄﺎء اﻟﻘﻴﺎس . أ رﺻﺎد ﻋﺎم 2024 ﺑﻌﺪ اﺳﺘﺨﺪام وﻳﺐ ﻷﻛﺜﺮ ﻣﻦ ﻋ ـ ﴩ ﺳـﺎﻋﺎت ﺑﻘﻠﻴﻞ ﰲ ﻋﺎم 2023 ﻣُﻨﺢ ﻓﺮﻳﻖ ﻣﺎدوﺳـﻮدان ﻓﱰة إﺿﺎﻓﻴﺔ ﺗﻘﺎرب ﺳﺖ ﺳﺎﻋﺎت ﻟﻠﺤﺼـﻮل ﻋﲆ ا ﺰﻳﺪ ﻣﻦ أﻃﻴﺎ ف اﻧﺘﻘﺎل اﻟﻨﺠﻢ K2-18b اﻟﻌﺎﺑﺮ أﻣﺎم ﻗﺮص ﻧﺠﻤﻪ . أُﺟﺮﻳﺖ ﻋﻤﻠﻴﺎت اﻟﺮﺻﺪ اﻟﺠﺪﻳﺪة ﺑـ 25 و 26 أﺑﺮﻳﻞ 2024 ﺑﺎﺳﺘﺨﺪام ﻣﻄﻴﺎف أ( ﻣ ي ) داة اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤـﺮاء ا ﺘﻮﺳـﻄﺔ ﺗﻌﻤـﻞ ﰲ ﻧﻄﺎق 5-28 ﻣﻴﻜﺮون .( ﻛﺎن اﻟﺒﺤﺚ ﻋﻦ اﻟﺒﺼﻤﺎت اﻟﺤﻴﻮﻳﺔ ﺑﺎﺳﺘﺨﺪام أداة ﻣﺨﺘﻠﻔﺔ ﻋﻦ اﻷدوات اﻟﺴﺎﺑﻘﺔ ﰲ ﻧﻄـﺎق اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء ا ﺠـﺎور وا ﻜﻤـﻞ ﻟﻠﻨﻄﺎق ا ﻟﺬي ﻳﻐﻄﻴﻪ ﻣﻄﻴﺎﻓَﺎ اﻟﻄﻴﻒ اﻵﺧـﺮان ﺳﻴُﻌﻄﻲ ﻣﺼـﺪاﻗﻴﺔ ﻹﺷـﺎرة ﺛﻨـﺎﺋﻲ ﻣﻴﺜﻴـﻞ اﻟﻜﱪﻳﺘﻴﺪ أو ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴـﻞ ﺛﻨـﺎﺋﻲ اﻟﻜﱪﻳﺘﻴـﺪ ﻇﻬﺮت ﻣﺮة أﺧﺮى . وﻋﻠّﻖ ﻣﺎدوﺳﻮدان ﻗﺎﺋﻼً " : ﻟﻘﺪ ﺟﺎءت اﻹﺷ ﺎرة واﺿﺤﺔً ﺟﻠﻴﺔً و ﻫﺬا دﻟﻴﻞٌ ﻣﺴﺘﻘﻞ ﺑﺎﺳـﺘﺨﺪام أداةٍ ﻣﺨ ﺘﻠﻔﺔٍ ﰲ ﻧﻄﺎقٍ ﻣﺨﺘﻠﻒٍ ﻣـﻦ اﻷﻃـﻮال ا ﻮﺟﻴﺔ ﺣﻴﺚ ﻻ ﻳﻮﺟﺪ ﺗﺪاﺧﻞٌ ﻣﻊ ا ﻼﺣﻈـﺎت اﻟﺴﺎﺑﻘﺔ ." ﻳﺒﺪو أن اﻟﺒﺤﺚ اﻟﺠﺪﻳﺪ ﻗﺪ ﻋﺰز ﻓﺮﺿﻴﺔ وﺟﻮد ﺣﻴﺎةٍ ﻋﲆ ﻛﻮﻛﺐ K2-18 b ﴍﻳﻄﺔ أن ﺗُﻌﺘﱪ ﺟﻤﻴﻊ اﻻﻓﱰاﺿﺎت اﻟﺘﻲ دﻓﻌـﺖ اﻟﺒـﺎﺣ ﺜ إﱃ ﺗﻔﺴ ﺗﻠﻚ اﻵﺛﺎر اﻟﺘﻲ ﻫﻲ ﰲ اﻟﺤﻘﻴ ﻘﺔ أﺛ ﻳﺔ ﻋﲆ أﻧﻬﺎ ﺑﺼﻤ ﺎت ﺣﻴﻮﻳﺔ . ﺻﺤﻴﺤﺔً ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 5 ﻣﻦ ﺑ ﻫﺬه اﻻﻓﱰاﺿﺎت، ﻫﻨﺎك ﻋﺪدٌ ﻗﻠﻴﻞٌ ﻣﻦ اﻟﺴﻴﻨﺎرﻳﻮﻫﺎت ا ﻘﱰﺣـﺔ ﰲ ﺷـﻜﻞ ﻣﻘـﺎﻻتٍ ﻋﻠﻤﻴﺔٍ ﻛﺘﺒﻬﺎ ﻣﺎدوﺳﻮدان ﻧﻔﺴـﻪ، وﻫـﻮ ﻣـﺎ ﻳﺜ ﺗﺴﺎؤﻻت ﺣﻮل ﻣـﺪى ﺣﻴﺎدﻳـﺔ اﻟﻨﺘـﺎﺋﺞ . ــــ ﻣﻤﺎ ﻳﺠﻌﻞ اﻻﺳﺘﻨﺘﺎﺟﺎت اﻟﺘﻲ ﺗﻮﺻﻞ إﻟﻴﻬﺎ ﻫﻮ وﻓﺮﻳﻘـﻪ ذاﺗﻴـﺔَ ا ﺮﺟﻌﻴـﺔ إﱃ ﺣـﺪٍ ﻣـﺎ . ﻫـﺬا ﻳﺴﺘﺪﻋﻲ ﺗﺪﻗﻴﻘﺎً أﻛﱪ ﻣـﻦ ا ﺠﺘﻤـﻊ اﻟﻌﻠﻤـﻲ ﻟﻀﻤﺎن ا ﻮﺿﻮﻋﻴﺔ .