Free Astronomy Magazine July-August 2025 ARABIC VERSION

Argumentsinfavoroflife on K2-18 b “Extraordinary claims require ex- traordinary evidence,” said Ca rl Sagan. This rule also applies to the claims of Madhusudhan and col- leagues.Let’sseeifthereisextraor- dinary evidence. The most concrete argument is linked to seeing the DMS (or DMDS) signal persist and even strengthen by changing spectrographs and ob- serving different wavelengths dur- ing the observations. It is unlikely that a spurious signal would reap- pearaftermorethanayearwithdif- ferent investigation conditions. Asecondpromisingaspecthastodo witharecentphotochemicalmodel- ing of K2-18 b (S.-M. Tsai et al., 2024), which suggests that signifi- cant quantities of DMS and DMDS canaccumulateintheatmosphere, up to levels several tens of times higher than those on Earth. Such high values would seem consistent withthedataextrapolatedbyMad- husudhan’s team. A third argument in favor derives from the limited knowledge we haveaboutthepossibleabioticgen- esis of DMS. As far as we know, there do not appear to be alterna- tiveprocessestothebioticonecapa- bleofproducingtheabundanceand concentration of DMS that re- searchersclaimtohaverecognized in the atmosphere of K2-18 b. It is true that a recent analysis of the datacollectedbytheRosettaprobe on comet 67P/Churyumov–Gerasi- menkohashighlightedthepresence of DMS in the gas jets, suggesting thepossibilityofapotentialabiotic source for that biosignature. How- ever, the quantity and current fre- quency of cometary impacts nec- essarytoaccountforthepresumed levels of DMS on K2-18 b make this an untenable solution. The Cam- bridgeresearchers’interpretationis also supported by the fact that if K2-18 b were to be a hycean, this planetarymodelwouldbemostcon- sistent with the scenario proposed by the team. Argumentsagainstlife on K2-18 b Itisalmostimpossibletolistinafew lines all the arguments that should scale down the optimism of Mad- husudhan and colleagues. We will limit ourselves to mentioning the less questionable ones. The first concerns the Webb Space Telescope,whichforseveralanalysts (suchas,forexample,thewell- known planetary scientist Sara Sea- ger of MIT) simply does not include allofthetechnologynecessarytoin- controvertiblydemonstratetheexis- tence of life on planets other than Earth. In principle, Webb can detect biosignatures through transmission spectroscopy, but the extrapolation of that data is complicated by ourpoor collective knowledge of exoat- mospheres and by the pollution ofthesignalduetostarlight.Each spectrum represents a highly medi- ated signal of chemical and physical atmospheric processes that manifest themselves in three dimensions but which, upon observation, are con- centrated in a single point sourcethatincludesonlystarandplanet . Asecondcriticalaspectconcernsthe verynatureofK2-18b.Theidea that it could be a hycean was putforwardwhenthecleartraceof methanedetectedbyHubblewas mistakenly attributed to water va- por. Today, we know that water is not present in any form in the upper atmosphere; if it is on the surface, and therefore K2-18 b is a hycean, theexistenceofsurfacewaterinany amount is a discovery that remainstobemade.Furthermore,even ifan oceanexistedbeneaththethickat- mospheric blanket, its waters might be subjected to conditions so ex- treme as to be uninhabitable. Another, even more robust argu- ment against the possibility of life onK2-18bhastodowithitsstar.As alreadymentioned,itisareddwarf, aclassofstarscharacterizedbyvery violentmagneticactivity,capableof generatingpowerfulflaresevensev- eral times over the course of an Earthday.Theflareslaunchintense flows of radiation into space in the form of a stellar wind, potentially shattering the atmospheres of the unfortunateplanets.Giventhesmall massesofthesestars,theirorbiting planets always find themselves within very short distance of these intenseradiationflows.Themostac- tive red dwarfs are the youngest ones, with ages of a few billion years:K2-18isabout3billionyears old,comparedtoa“lifeexpectancy” of trillions of years. It is therefore fully active, and the phenomena that affect it can contaminate the spectracollectedbytelescopes,as happens, for example, with the TRAPPIST-1 system. Furthermore, even leaving aside the devastating effectsofstellaractivity,weknow that red dwarf planets are often gravitationally forced to always turn the same hemisphere towards the star.Thisisnotanoptimalcondition forlifeasweknowit(butifitpro- ducesDMS,itcan’tbeverydifferent from what we know.) A further aspect of the issue that clashes with the conclusions of Mad- husudhan’s team is the presumed universal validity of DMS as a biosig- nature.WhileitistruethatonK2-18 b it can hardly have been conferred bycountlesscomets,itisequallytrue JULY-AUGUST2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 10 ﺣﺠﺞٌ ﺗﺪﻋﻢوﺟﻮد ﺣ ﺎةﻋﻠﻰ اﻟ ﻮﻛﺐ K2-18 b اﻟﻨﻈﺎم اﻟﻨ ﻤﻲ K2-18 وﻳ ﺪو اﻟ ﻮﻛﺐ "b " ﻓــــﻲ اﻟﻤﻘﺪﻣــــﺔ واﻟ ﻮﻛـــــﺐ "c " ﻤــــﺮأﻣـــــﺎم اﻟﻘﺰم اﻷ ﻤﺮ ﻓﻲﻫﺬا اﻟﺮﺳﻢ اﻟﺘﺨ ﻠﻲ . ﻗﺎل ﻛﺎرل ﺳﺎ : " ﺎنﻏ اﻻدﻋـﺎءات اﻻﺳـﺘﺜﻨﺎﺋﻴﺔ ﺗﺘﻄﻠ ـﺐ أدﻟـﺔً اﺳـﺘﺜﻨﺎﺋﻴﺔ ." وﺗﻨﻄﺒـﻖ ﻫـﺬه اﻟﻘﺎﻋﺪة أﻳﻀًـﺎ ﻋـﲆ ادﻋـﺎءات ﻣﺎدوﺳـﻮدان . وزﻣﻼﺋﻪ ﻟﻨﺮَ إن ﻛﺎﻧﺖ ﻫﻨﺎك أدﻟﺔ اﺳـﺘﺜﻨﺎﺋﻴﺔ . ﺗﺮﺗﺒﻂ اﻟﺤﺠﺔ اﻷﻛﺜﺮ واﻗﻌﻴﺔً ﺑﺮؤﻳـﺔ إﺷـﺎرة ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴﺪ أو ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ ﺛﻨـﺎﺋﻲ اﻟﻜﱪﻳﺘﻴﺪ وﻫﻲ ﺗﺴﺘﻤﺮ ﺑﻞ وﺗـﺰداد ﻗـﻮةً ﻣـﻦ ﺧﻼل ﺗﻐﻴ أﺟﻬـﺰة ﻗﻴـﺎس اﻟﻄﻴـﻒ ورﺻـﺪ أﻃﻮال ﻣﻮﺟﻴﺔ ﻣﺨﺘﻠﻔﺔ أﺛﻨﺎء ﻋﻤﻠﻴﺎت اﻟﺮﺻـﺪ ﻟﺬﻟﻚ ﻣﻦ ﻏ ا ﺮﺟﺢ أن ﺗﻈﻬﺮ إﺷﺎرة زاﺋﻔـﺔ ﺑﻌﺪ أﻛﺜﺮ ﻣﻦ ﻋﺎم ﻣ ﻊ اﺧﺘﻼف ﻇﺮوف اﻟﺒﺤﺚ . ﻫﻨ ـﺎك ﺟﺎﻧــﺐ آﺧ ـﺮ ﻇﻬ ـﺮ ﻣ ـﻊ اﻟ ﻨﻤﺬﺟــﺔ اﻟﻜﻴﻤﻴﺎﺋﻴﺔ اﻟﻀﻮﺋﻴﺔ ﻟ ﻠﻜﻮﻛﺐ K2-18 b ﻣﻤﺎ ﻳﺸ إﱃ أن ﻛﻤﻴ ﺎت ﻛﺒ ة ﻣﻦ ﺛﻨـﺎﺋﻲ ﻣﻴﺜﻴـﻞ اﻟﻜﱪﻳﺘﻴﺪ و ﺛﻨـﺎﺋﻲ ﻣﻴﺜﻴـﻞ ﺛﻨـﺎﺋﻲ اﻟﻜﱪﻳﺘﻴـﺪ ﻳﻤﻜــﻦ أن ﺗـﱰاﻛﻢ ﰲ اﻟﻐــﻼف اﻟﺠـﻮي ﺣﺘـﻰ ﻣﺴﺘﻮﻳﺎتٍ أﻋﲆ ﺑﻌـ ـ ﴩات ا ـﺮات ﻣـﻦ ﺗﻠـﻚ ا ﻮﺟﻮدة ﻋﲆ اﻷرض . ﺗﺒﺪو ﻫﺬه اﻟﻘﻴﻢ اﻟﻌﺎﻟﻴﺔ ﻣﺘﺴﻘﺔ ﻣﻊ اﻟﺒﻴﺎﻧـﺎ ت اﻟﺘﻲ اﺳﺘﻨﺒﻄﻬﺎ ﻓﺮﻳﻖ ﻣﺎدﻫﻮﺳـﻮدان وﺗﻨﺒـﻊ ﺣﺠﺔ ﺛﺎﻟﺜﺔ ﻣﺆﻳـﺪة ﻣـﻦ ﻣﻌﺮﻓ ﺘﻨـﺎ ا ﺤـﺪ ودة ﺑﺈﻣﻜﺎﻧﻴﺔ اﻟﺘﻜـﻮّن اﻟﻼﺣﻴـﻮي ﻟ ﺜﻨـﺎﺋﻲ ﻣﻴﺜﻴـﻞ اﻟﻜﱪﻳﺘﻴﺪ . ﻋﲆ ﺣﺪ ﻋﻠﻤﻨـﺎ ﻻ ﻳﺒـﺪو أن ﻫﻨـﺎك ﻋﻤﻠﻴﺎت ﺑﺪﻳﻠﺔ ﻟﻠﻌﻤﻠﻴﺔ اﻟﺤﻴﻮﻳﺔ ﻗـﺎدرة ﻋـﲆ إﻧﺘﺎج وﻓﺮة وﺗﺮﻛﻴﺰ ﺛﻨـﺎﺋﻲ ﻣﻴﺜﻴـﻞ اﻟﻜﱪﻳﺘﻴـﺪ اﻟﺘﻲ ﻳﺪﻋﻲ اﻟﺒﺎﺣﺜﻮن أﻧﻬﻢ ﺗﻌﺮﻓـﻮا ﻋﻠﻴﻬـﺎ ﰲ اﻟﻐﻼف اﻟﺠﻮي ﻟ ﻠﻜﻮﻛﺐ K2-18 b. . ﺻــﺤﻴﺢ أن ﺗﺤﻠــﻴﻼً ﺣــﺪﻳﺜ ﺎً ﻟﻠﺒﻴﺎﻧــﺎت اﻟﺘـﻲ ا ﺟﻤﻌﻬﺎ ﺴﺒﺎر روزﻳﺘﺎ ﻣﻦ ﻋﲆ ا ﺬﻧﺐ 67/P ﺗﺸﻮرﻳﻮﻣﻮف - ﺟ اﺳﻴﻤﻨﻜﻮ ﻗﺪ ﺳﻠّﻂ اﻟﻀﻮء ﻋﲆ وﺟﻮد ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴﺪ ﺎ ﰲ ﻧﻔ ﺛـﺎت اﻟﻐﺎز ﻣﻤﺎ ﻳﺸـ إﱃ اﺣﺘﻤـﺎل وﺟـﻮد ﻣﺼـﺪر ﻻﺣﻴﻮي ﻣﺤﺘ ﻤﻞ ﻟﺘﻠﻚ اﻟﺒﺼﻤﺔ اﻟﺤﻴﻮﻳﺔ . وﻣﻊ ذﻟﻚ، ﻓﺈن ﻛﻤﻴـﺔ وﺗﻜـﺮار اﺻـﻄﺪاﻣﺎت ا ﺬﻧﺒﺎت اﻟﻼ زﻣﺔ ﻟﺘﻔﺴ ا ﺴﺘﻮﻳﺎت ا ﻔﱰﺿﺔ ﻣﻦ ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴـﻞ اﻟﻜﱪﻳﺘﻴـﺪ ا ﺮﺻـﻮدة ﻋـﲆ اﻟﻜﻮﻛﺐ K2-18 b ﺗﺠﻌـﻞ ﻫـﺬا اﻟﺤـﻞ ﻏـ ﻣﻘﺒﻮل ﻋﲆ اﻹﻃﻼق ﻣﺎ . ﻳﺪﻋﻢ ﺗﻔﺴ ﺑـﺎﺣﺜﻲ ﻛﺎﻣﱪﻳﺪج أﻳﻀ ﺎً ﺣﻘﻴﻘﺔ أﻧﻪ إذا ﻛﺎن K2-18 b ﻛﻮﻛﺒًـﺎ ﻣـﻦ ﻓﺌـﺔ ﻫﻴﺸـﻴﺎن ﻓﺴـﻴﻜﻮن ﻫـﺬا اﻟﻨﻤــﻮذج اﻟﻜــﻮﻛﺒﻲ اﻷﻛﺜــﺮ اﺗﺴــﺎﻗًﺎ ﻣــﻊ ــــــــ اﻟﺴـﻴﻨﺎرﻳﻮ اﻟـﺬي اﻗﱰﺣـﻪ اﻟﻔﺮﻳـﻖ ﺧﺎﺻـﺔً ﺑﺎﻟﻨﻈﺮ إﱃ اﻟﺘﺤﺪﻳﺎت اﻟﺘﻲ ﻳﻮاﺟﻬﻬـﺎ ﺗﻔﺴـ ا ــﺬﻧﺒﺎت ﻛﻤﺼــﺪر ﻣﺤﺘ ﻤــﻞ ﻟﻠﻤﺮﻛﺒـــﺎت اﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﻳﺼﺒﺢ أﻛﺜﺮ ﻣﻨﻄﻘﻴﺔ وﻣﻮﺛﻮﻗﻴﺔ . ـاﻟ ﺤﺠﺞﺿﺪ وﺟﻮد ﺣ ﺎة ﻋﻠﻰ اﻟ ﻮﻛﺐ K2-18 b ﻳﻜﺎد ﻳﻜﻮن ﻣﻦ ا ﺴﺘﺤﻴﻞ ﴎد ﺟﻤﻴﻊ اﻟﺤﺠﺞ اﻟﺘ ـﻲ ﻣ ـﻦ ﺷ ـﺄﻧﻬﺎ أن ﺗُﻘﻠــﻞ ﻣ ـﻦ ﺗﻔــﺎؤل ﻣﺎدوﺳ ـﻮدان وزﻣﻼﺋــﻪ ﰲ ﺑﻀــﻌﺔ أﺳــﻄﺮ . ﺳﻨﻘﺘﴫـ ﻋـﲆ ذﻛـﺮ اﻟﺤﺠـﺞ اﻷﻗـﻞ إﺛـﺎرةً ﻟﻠﺸــﻜﻮك . اﻷول ﻳﺘﻌﻠــﻖ ﺑﺘﻠﺴــﻜﻮب و ﻳــﺐ اﻟﻔﻀﺎﺋﻲ واﻟﺬي، ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻌﺪﻳﺪ ﻣﻦ ا ﺤﻠﻠ ) ﻣﺜﻞ ﻋﺎ ﺔ اﻟﻜﻮاﻛﺐ اﻟﺸﻬ ة ﺳـﺎرة ﺳـﻴﺠﺮ ﻣﻦ ﻣﻌﻬﺪ ﻣﺎﺳﺎﺗﺸﻮﺳـﺘﺲ ﻟﻠﺘﻜﻨﻮﻟﻮﺟﻴـﺎ ﻻ ( ﻳﺘﻀﻤﻦ ﺑﺒﺴﺎﻃﺔ ﺟﻤﻴـﻊ اﻟﺘﻘﻨﻴـﺎت اﻟﻼزﻣـﺔ ﻹﺛﺒﺎت وﺟﻮد ﺣﻴﺎة ﻋﲆ ﻛﻮاﻛـﺐ أﺧـﺮى ﻏـ اﻷرض ﺑﺸﻜﻞ ﻗﺎﻃﻊ . ﻣـﻦ ﺣﻴـﺚ ا ﺒــﺪأ ﻳﻤﻜـﻦ ﻟﺘﻠﺴـﻜﻮب وﻳـﺐ اﻛﺘﺸــﺎف اﻟﺒﺼـﻤﺎت اﻟﺤﻴ ﻮﻳ ـ ﺔ ﻣـﻦ ﺧـﻼل اﻟﺘﺤﻠﻴﻞ اﻟﻄﻴﻔﻲ اﻟﻨﺎﻓﺬ ﻟﻜـﻦ اﺳـﺘﻘﺮاء ﻫـﺬه اﻟﺒﻴﺎﻧﺎت ﻳ ﻌﻘّﺪه ﺿـﻌﻒ ﻣﻌﺮﻓﺘﻨـﺎ اﻟﺠﻤﺎﻋﻴـﺔ ﺑﺎﻟﻐﻼف اﻟﺠﻮي اﻟﺨـﺎرﺟ ﻲ وﺗﻠـﻮث اﻹﺷـﺎرة ﺑﺴﺒﺐ ﺿﻮء اﻟﻨﺠﻮم . ﻳﻤﺜـﻞ ﻛــﻞ ﻃﻴـﻒ إﺷـﺎرةً ﻋﺎﻟﻴـﺔَ اﻟﺘﻮﺳـﻂ ﻟﻌﻤﻠﻴﺎت ﺟﻮﻳﺔ ﻛﻴﻤﻴﺎﺋﻴﺔ وﻓﻴﺰﻳﺎﺋﻴﺔ ﺗﺘﺠﲆ ﰲ ﺛﻼﺛﺔ أﺑﻌـﺎد وﻟﻜﻨﻬـﺎ ﻋﻨـﺪ اﻟﺮﺻـﺪ ﺗﱰﻛـﺰ ﰲ ﻣﺼﺪ ر ﻧﻘﻄﻲ واﺣﺪ ﻳﺸﻤﻞ اﻟـﻨﺠﻢ واﻟﻜﻮﻛـ ﺐ ﻓﻘﻂ وﻫﻨﺎك ﺟﺎﻧ ﺐ ﺣﺎﺳﻢ ﺛﺎنٍ ﻳﺘﻌﻠﻖ ﺑﻄﺒﻴﻌﺔ اﻟﻜﻮﻛﺐ K2-18 b . ذاﺗﻬﺎ ﻃُ ﺮﺣﺖ ﻓﻜﺮةُ أﻧﻪ ﻗﺪ ﻳﻜﻮن ﻛﻮﻛـﺐ ﻫﻴ نﺎﻴﺸـ ﻧ ﻋﻨﺪﻣﺎ ﻨﺴﺐ أﺛﺮ ا ﻴﺜﺎن اﻟﻮاﺿﺢ اﻟﺬي رﺻﺪه ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ ﺧﻄﺄً إﱃ ﺑﺨﺎر ا ﺎء . ﻧﻌﻠﻢ اﻟﻴﻮم أن ا ﺎء ﻏ ﻣﻮﺟﻮد ﺑﺄي ﺷﻜﻞ ﻣﻦ اﻷﺷﻜﺎل ﰲ ا ﻟ ﻐﻼف اﻟﺠﻮي اﻟﻌﻠﻮي ﻓﺈذا ﻛـﺎن ﻣ ﻮﺟﻮدًا ﻋﲆ اﻟﺴﻄﺢ وﺑﺎﻟﺘﺎﱄ ﻳ ﻌﺘﱪ اﻟﻜﻮﻛﺐ K2-18 b ﻛﻮﻛﺐ ﻫﻴ نﻴﺎﺸ ﻓﺈن وﺟـﻮد ا ـﺎء اﻟﺴﻄﺤﻲ ﺑﺄي ﻛﻤﻴﺔ ﻫـﻮ اﻛﺘﺸـﺎف ﻻ ﻳـﺰال ﻳﺘﻌ ﺗﺤﻘﻴﻘﻪ . ﻋﻼوة ﻋﲆ ذﻟﻚ ﺣﺘﻰ ﻟﻮ وُﺟـ ﺪ ﻣﺤﻴﻂٌ ﺗﺤﺖ اﻟﻐﻄﺎء اﻟﺠـﻮي اﻟﺴـﻤﻴﻚ ﻓﻘـﺪ ﺗﻜﻮن ﻣﻴﺎﻫﻪ ﻣﻌﺮﺿﺔً ﻟﻈﺮوف ﻗﺎﺳ ﻴﺔ ﻟﻠﻐﺎﻳﺔ ﺗﺠﻌﻠﻪ ﻏ ﺻﺎﻟﺢ ﻟ ﻠﺤﻴﺎة . ﻫﻨﺎك ﺣﺠﺔ أﺧﺮى ـــــــــــــــــــــــــــــــــــــ أﻛﺜﺮ ﻗ ﻮة ﺿـﺪ إﻣﻜﺎﻧﻴـﺔ وﺟـﻮد ﺣﻴـﺎة ﻋـﲆ اﻟﻜﻮﻛﺐ K2-18 b ﺗﺘﻌﻠﻖ ﺑﻨﺠﻤﻪ . ﻓﻜﻤﺎ ذﻛـﺮ ﺳﺎﺑﻘًﺎ ﻫﻮ ﻗﺰم أﺣﻤﺮ وﻫﻮ ﻓﺌﺔ ﻣـﻦ اﻟﻨﺠـﻮم ﺗ ﺘﻤﻴﺰ ﺑﻨﺸﺎط ﻣﻐﻨﺎﻃﻴﴘ ﻋﻨﻴﻒ ﻟﻠﻐﺎﻳﺔ ﻗﺎدر ﻋﲆ ﺗﻮﻟﻴﺪ ﺗﻮﻫﺠﺎت ﻗﻮﻳﺔ ﺣﺘـﻰ ﻋـﺪة ﻣـﺮات ﺧﻼل ﻳﻮم أرﴈواﺣﺪ . ﺗُﻄﻠﻖ ﻫﺬه اﻟﺘﻮﻫﺠﺎت ﺗـﺪﻓﻘﺎت ﻛﺜﻴﻔـﺔ ﻣـﻦ اﻹﺷﻌﺎ ع إﱃ اﻟﻔﻀﺎء ﻋﲆ ﺷﻜ ﻞ رﻳـﺎح ﻧﺠﻤﻴـﺔ ﻣﻤﺎ ﻗﺪ ﻳﺤﻄﻢ أﺟﻮاء ﻫﺬه اﻟﻜﻮاﻛﺐ . اَ ﻧﻈﺮ ﻟﺼﻐﺮ ﻛﺘﻞ ﻫﺬه اﻟﻨﺠﻮم ﻓـﺈن اﻟﻜﻮاﻛـﺐ اﻟﺘﻲ ﺗﺪور ﺣﻮﻟﻬﺎ ﺗﺠﺪ ﻧﻔﺴﻬﺎ داﺋﻤ ﺎً ﻋﲆ ﺑُﻌـﺪ ﻣﺴﺎﻓﺔ ﻗﺼـ ة ﺟـﺪ اً ﻣـﻦ ﻫـﺬه اﻟﺘـﺪﻓﻘﺎت اﻹﺷﻌﺎﻋﻴﺔ اﻟﻜﺜﻴﻔـﺔ . أﻣـﺎ اﻷﻗـﺰام اﻟﺤﻤـﺮا ء اﻷﻛﺜﺮ ﻧﺸﺎﻃًﺎ ﻓﻬﻲ اﻷﺻﻐﺮ ﺳﻨﺎً ﺣﻴـﺚ ﻳﺒﻠـﻎ ﻋﻤﺮﻫﺎ ﺑﻀﻌﺔ ﻣﻠﻴﺎرات ﻣ ﻦ اﻟﺴﻨ : ﻳﺒﻠﻎ ﻋﻤﺮ اﻟﻜﻮﻛــﺐ K2-18 ﺣـﻮاﱄ 3 ﻣﻠﻴ ـﺎرات ﺳـﻨﺔ ﻣﻘﺎرﻧــﺔً ﺑﻤﺘﻮﺳــﻂ ﻋﻤــﺮ ﻣﺘﻮﻗــﻊ ﻳﺒﻠــﻎ ﺗﺮﻳﻠﻴﻮﻧ ﺎت اﻟﺴﻨ . ﻟﺬﻟﻚ ﻓﻬـﻮ ﻧﺸـﻂ ﺗﻤﺎﻣـﺎً واﻟﻈﻮاﻫﺮ اﻟﺘﻲ ﺗﺆﺛﺮ ﻋﻠﻴﻪ ﻗﺪ ﺗُﻠﻮث اﻷﻃﻴـﺎف ا ﻟﺘﻲ ﺗﺠﻤﻌﻬﺎ اﻟﺘﻠﺴﻜﻮﺑﺎت ﻛﻤﺎ ﻳﺤـﺪث ﻋـﲆ ﺳﺒﻴﻞ ا ﺜﺎل ﻣﻊ ﻧﻈﺎم ﺗﺮاﺑﻴﺴﺖ -1 . ﻋﻼوة ﻋﲆ ذﻟﻚ ﺣﺘﻰ ﻣﻊ ﺗﺠﺎ ﻫ ﻞ اﻵﺛﺎر ا ﺪﻣﺮة ﻟﻠﻨﺸﺎط اﻟﻨﺠﻤﻲ ﻧﻌﻠـﻢ أن اﻟﻜﻮاﻛـﺐ اﻟﺘﺎﺑﻌـﺔ ﻟﻸﻗﺰام اﻟﺤﻤﺮاء ﻏﺎﻟﺒ ﻫـﺎ ﺠﱪ ﻣﺎ ﺗ ﺎً ﺟﺎذﺑﻴﺘﻬـﺎ اﻟﻘﻮﻳﺔ ﻋﲆ ﻣﻮاﺟﻬﺔ اﻟﻨﺠﻢ ﺑﺠﺎﻧﺐ واﺣﺪ ﻋﲆ اﻟﺪوام إن . ﻫﺬه ﻟﻴﺴﺖ ﺣﺎﻟـﺔ ﻣﺜﺎﻟﻴـﺔ ﻟﻠﺤﻴـﺎة ﻛﻤﺎ ﻧﻌﺮﻓﻬﺎ ﻋـﲆ اﻷرض ) وﻟﻜـﻦ إذا أﻧﺘﺠـﺖ ﺛﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴﺪ ﻓﻠﻦ ﺗﻜـﻮن ﻃﺒﻴﻌﺘﻬـﺎ ﻣﺨﺘﻠ اً ﻔﺔ ﻛﺜ ﻋﻤﺎ ﻧﻌﺮﻓﻪ .( إﱃ ﺟﺎﻧﺐ ﻣﺎ ﺳﺒﻖ ﻓﺈن ﺟﺎﻧﺒ ﺎً آﺧﺮ ﻣﻦ ا ﺴﺄﻟﺔ ﻳﺘﻌﺎرض ﻣﻊ اﺳﺘﻨﺘﺎﺟﺎت ﻓﺮﻳﻖ ﻣﺎدوﺳـﻮدان وﻫﻮ اﻓﱰاض اﻟﺼﻼﺣﻴﺔ اﻟﻌﺎ ﻴﺔ ﻟﺜﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴﺪ ﻛﺒﺼﻤﺔ ﺣﻴﻮﻳﺔ . وﰲ ﺣ أن ﻣـﻦ اﻟﺼـﻌﺐ أن ﻳﻜـﻮن ﻋـﺪد ﻻ ﻳﺤﴡ ﻣﻦ ا ﺬﻧﺒﺎت ﻗـﺪ إﱃ ﺟﻠﺒﻬـﺎ اﻟﻜﻮﻛـﺐ K2-18b ﻓﻤﻦ اﻟﺼﺤﻴﺢ أﻳﻀ ﺎً أﻧـﻪ ﻻ ﻳﻤﻜـﻦ اﺳﺘ ﺒﻌﺎد أﺻﻞ ﻏ ﺣﻴﻮي ﺗﻤﺎﻣﺎً ﻟﺜﻨﺎﺋﻲ ﻣﻴﺜﻴﻞ اﻟﻜﱪﻳﺘﻴﺪ ﻣﻤـﺎ ﻳﺘﻄﻠـﺐ ا ﺰﻳـﺪ ﻣـﻦ اﻟﺒﺤـﺚ واﻟﺘﺤﻘﻖ اﻟﺪﻗﻴﻖ ﻗﺒﻞ اﻟﺠﺰم . ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 5 [ESO/M.Kornmesser/N. Risinger (skysurvey.org )]