Free Astronomy Magazine July-August 2026 ARABIC VERSION

the magnesium and silicon content of the exoplanet’s atmosphere. This isthefirsttimesuchameasurement hasbeenmade,andthedatareveal that WASP-189 b shares the same magnesium-to-silicon ratio asits host star. This finding provides the first observational evidence of a widely adopted assumption about planetformation,andopensanew route to understand how exoplan- ets form and evolve. “These discoveries showGemini’s ability to help us understand the characteristics of the remarkable zoo of exoplanets in our solar neighborhood,” says Chris Davis, NSF Program Director for NOIRLab. “Suchdiscoveriesareonlypossible because of Gemini’s cutting-edge instruments.” Hot giant planets like WASP-189 b are thought to have an outer layer ofgasthathasachemicalcomposi- tioninfluencedbythediskofmate- rialinwhichtheyformed,knownas protoplanetary disks. And re- searchers assume that the ratio of rock-forming elements in a proto- planetary disk matches that of the host star, since the two were born from the same primordial cloud of material. This inferred chemical link between a star and the planets thatform around it is commonly used to modelthecompositionofrockyex- oplanets. This link was previously based on measurements within our Solar System, and it had not been directly observed on planets else- where, until now. “WASP-189 b gives us a much- needed observational anchor in our understanding of terrestrial planet formation since it offers a meas- urable quantity that validates the presumed resemblance of stellar composition and the proportion of rocky material around host stars usedtoformplanets,” saysSanchez. Thisassumptionisnotonlyuseful for understanding planetforma- tion, but it is also foundational to the field of astrobiology, which in- cludes the study of habitable envi- ronments in the Solar System. By measuring the chemical composi- tionofastar,scientistscaninferthe abundances of rock-forming ele- ments in the star’s exoplanets, which can dictate the geochemical conditionsthatmakeaplanethab- itable.Forinstance,therock-form- ing elements in Earth are in-part responsibleforourprotectivemag- neticfield,platetectonics,anddriv- ing the release of life-sustaining chemicals into our atmosphere, oceans, and soil. As the exoplanet field looks to- wards the characterization of ter- restrial planets, and seeks to eluci- date the habitable conditions of rocky worlds, empirical evidence validating the relationship between stellar and planetary compositions represents a fundamental step for- ward. And the level of spectral res- olution necessary for these types of studies is currently only available on ground-based telescopes. “Our study demonstrates the capa- bility of ground-based, high-resolu- tion spectrographs to constrain critical species like magnesium and silicon, which are two elemental building blocks from which rocky planets form,” says study co-author MichaelLine,AssociateProfessorat ASU. “This advancing capability opens an entirely new dimension in our study of exoplanet atmos- pheres.” Furthermulti-wavelength,high-res- olution observations to study exo- planet atmospheres like that of WASP-189 b will help reveal the larger chemical inventory that exists within distant worlds. Such studies willenabledeeperinsightsintothe conditions that govern planetary origins, evolution, and potential habitability.     JULY-AUGUST2026 - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 6 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 23 داﺧﻞ اﻟﻨﻈﺎم اﻟﺸﻤﴘ وﺧﺎرﺟﻪ . ﻓﻌﻨﺪﻣﺎ ﻳﺘﻤﻜﻦ اﻟﻌﻠﻤﺎء ﻣﻦ ﻗﻴـﺎس اﻟﱰﻛﻴـﺐ اﻟﻜﻴﻤﻴﺎﺋﻲ ﻟﻨﺠﻢ ﻣﺎ ﻳﻤﻜﻨﻬﻢ اﺳـﺘﻨﺘﺎج وﻓـﺮة اﻟﻌﻨﺎﴏ ا ﻜﻮِﻧﺔ ﻟﻠﺼﺨﻮر ﰲ اﻟﻜﻮاﻛـﺐ اﻟﺘـﻲ ﺗﺪور ﺣﻮﻟﻪ وﻫﻮ أﻣﺮ ﻳﺆﺛﺮ ﺑﺸـﻜﻞ ﻣﺒـﺎﴍ ﰲ ﻃﺒﻴﻌﺔ ﺟﻴﻮﻟﻮﺟﻴﺔ ﻫـﺬه اﻟﻌـﻮاﻟﻢ وإﻣﻜﺎﻧﻴـﺔ ﻣﻼءﻣﺘﻬﺎ ﻟﻠﺤﻴﺎة . ﻓﻌﲆ ﺳﺒﻴﻞ ا ﺜﺎل أﺳﻬﻤﺖ اﻟﻌﻨﺎﴏ اﻟﺼﺨﺮﻳﺔ ا ﻮﺟـــﻮدة ﰲ اﻷرضﰲ ﺗﻜـــﻮﻳﻦ ا ﺠـــﺎل ا ﻐـ ـ ﻨﺎﻃﻴﴘ اﻟـﻮاﻗﻲ ﻟﻠﻜﻮﻛـﺐ وﰲ ﻧﺸـﺎط اﻟﺼﻔﺎﺋﺢ اﻟﺘﻜﺘﻮﻧﻴﺔ وﻛﺬﻟﻚ ﰲ إﻃﻼق اﻟﻌﻨﺎﴏ اﻟﻜﻴﻤﻴﺎﺋﻴﺔ اﻟـ ـ ﴬورﻳﺔ ﻟﻠﺤﻴـﺎة إﱃ اﻟﻐـﻼف اﻟﺠﻮي وا ﺤﻴﻄﺎت واﻟﱰﺑﺔ . وﻣﻊ اﻧﺘﻘﺎل أﺑﺤﺎث اﻟﻜﻮاﻛﺐ اﻟﺨﺎرﺟﻴﺔ ﻧﺤـﻮ دراﺳﺔ اﻟﻜﻮاﻛﺐ اﻟﺼﺨﺮﻳﺔ اﻟﺸﺒﻴﻬﺔ ﺑـﺎﻷرض وﺗﻘﻴ ـﻴﻢ ﻗﺎﺑﻠﻴﺘﻬ ـﺎ ﻟﻠﺤﻴ ـﺎة ﻳﻤﺜ ـﻞ اﻟﺘﺤﻘ ـﻖ اﻟﺮﺻﺪي ﻣﻦ اﻟﻌﻼﻗـﺔ ﺑـ ﺗﺮاﻛﻴـﺐ اﻟﻨﺠـﻮم وﻛﻮاﻛﺒﻬﺎ ﺧﻄﻮة أﺳﺎﺳﻴﺔ ﻧﺤﻮ ﺑﻨـﺎء ﻧ ﻤـﺎذج أﻛﺜﺮ دﻗﺔ ﻟﻠﻌﻮاﻟﻢ اﻟﺒﻌﻴﺪة . أوﺿﺢ اﻟﺒﺎﺣﺚ ا ﺸﺎرك ﻣﺎﻳﻜﻞ ﻻﻳـﻦ اﻷﺳـﺘﺎذ ا ﺸﺎرك ﰲ ﺟﺎﻣﻌـﺔ وﻻﻳـﺔ أرﻳﺰوﻧـﺎ :» ﺗُﻈﻬـﺮ دراﺳﺘﻨﺎ ﻗﺪرة ا ﻄﻴﺎﻓﺎت اﻷرﺿﻴﺔ ﻋﺎﻟﻴﺔ اﻟﺪﻗﺔ ﻋﲆ ﻗﻴﺎس ﻋﻨﺎﴏ أﺳﺎﺳﻴﺔ ﻣﺜﻞ ا ﻐﻨﻴﺴـﻴﻮم واﻟﺴﻴﻠﻜﻮن ، وﻫﻤﺎ ﻣـﻦ اﻟﻠﺒﻨـﺎت اﻟﻜﻴﻤﻴﺎﺋﻴـﺔ اﻟﺮﺋﻴﺴ ـﻴﺔ اﻟﺘــﻲ ﺗﺘﻜــﻮن ﻣﻨﻬــﺎ اﻟﻜ ﻮاﻛــﺐ اﻟﺼﺨﺮﻳﺔ . « وأﺿﺎف أن ﻫﺬه اﻟﻘﺪرات ا ﺘﻨﺎﻣﻴﺔ ﺗﻔﺘﺢ ﺑﻌﺪاً ﺟﺪﻳﺪاً ﺑﺎﻟﻜﺎﻣﻞ ﰲ دراﺳﺔ اﻷﻏﻠﻔـﺔ اﻟﺠﻮﻳﺔ ﻟﻠﻜﻮاﻛﺐ اﻟﺨﺎرﺟﻴﺔ . ﺗﻤﺜﻞ ﻫﺬه اﻟﻨﺘﺎﺋﺞ ﺧﻄﻮة ﻣﻬﻤﺔ ﻧﺤﻮ اﻻﻧﺘﻘﺎل ﻣﻦ ﻣﺠﺮد اﻛﺘﺸﺎف اﻟﻜﻮاﻛـﺐ اﻟﺨﺎرﺟﻴـﺔ إﱃ دراﺳﺔ ﺧﺼﺎﺋﺼﻬﺎ اﻟﻔﻴﺰﻳﺎﺋﻴـﺔ واﻟﻜﻴﻤﻴﺎﺋﻴـﺔ ﺑﺎﻟﺘﻔﺼﻴﻞ . ﻓﻜﻞ ﻋﻨـ ـ ﴫ ﻳﺮﺻـﺪ ﰲ اﻟﻐـﻼف اﻟﺠﻮي ﻟﻜﻮﻛﺐ ﺑﻌﻴﺪ ﻳﻀﻴﻒ ﻣﻌﻠﻮﻣﺔ ﺟﺪﻳـﺪة ﻋﻦ ﺗﺎرﻳﺨﻪ وﺑﻴﺌﺔ ﺗﺸﻜﻠﻪ ﻛﻤﺎ ﻳﺴﺎﻋﺪ اﻟﻌﻠﻤﺎء ﻋﲆ اﺧﺘﺒﺎر اﻟﻨﻤﺎذج اﻟﻨﻈﺮﻳﺔ ا ﺘﻌﻠﻘﺔ ﺑﺘﻜﻮﻳﻦ اﻟﻜﻮاﻛﺐ وﻫﺠﺮﺗﻬﺎ وﺗﻔﺎﻋﻠﻬـﺎ ﻣـﻊ أﻗـﺮاص اﻟﻐﺎز واﻟﻐﺒﺎر اﻟﺘﻲ وﻟﺪت ﻣﻨﻬﺎ . ﻳﺘﻮﻗﻊ اﻟﺒﺎﺣﺜﻮن أن ﺗﺴﻬﻢ ﻋﻤﻠﻴـﺎت اﻟﺮﺻـﺪ ا ﺴﺘﻘﺒﻠﻴﺔ ﻣﺘﻌﺪدة اﻷﻃﻮال ا ﻮﺟ ﻴـﺔ وﻋﺎﻟﻴـﺔ اﻟﺪﻗﺔ ﰲ اﻟﻜﺸﻒ ﻋـﻦ ﻣﺰﻳـﺪ ﻣـﻦ اﻟﺘﻔﺎﺻـﻴﻞ ا ﺘﻌﻠﻘ ـﺔ ﺑــﺎ ﺨﺰون اﻟﻜﻴﻤﻴ ـﺎﺋﻲ ﻟﻠﻜﻮاﻛــﺐ اﻟﺒﻌﻴﺪة ﻣﻤﺎ ﺳﻴﺘﻴﺢ ﻓﻬﻤـﺎً أﻋﻤـﻖ ﻟﻠﻈـﺮوف اﻟﺘﻲ ﺗﺤﻜﻢ ﻧﺸﺄة اﻟﻜﻮاﻛﺐ وﺗﻄﻮرﻫـﺎ ورﺑﻤـﺎ ﻬﺎ ﻗﺎﺑﻠﻴﺘ ﻻﺣﺘﻀﺎن اﻟﺤﻴﺎة . اﻟﻘﻴﺎس ﻣﺒﺎﴍة . وأﻇﻬﺮت اﻟﻨﺘﺎﺋﺞ أن ﻧﺴـﺒﺔ ا ﻐﻨﻴﺴﻴﻮم إﱃ اﻟﺴﻴﻠﻜﻮن ﰲ اﻟﻐـﻼف اﻟ ﺠـﻮي ﻟﻠﻜﻮﻛﺐ WASP-189 b ﺗﺘﻄﺎﺑﻖ ﻣﻊ اﻟﻨﺴـﺒﺔ ا ﻮﺟﻮدة ﰲ ﻧﺠﻤﻪ ا ﻀﻴﻒ . وﻳﻤﺜﻞ ﻫﺬا اﻻﻛﺘﺸﺎف أول دﻟﻴﻞ رﺻﺪي ﻣﺒﺎﴍ ﻳﺪﻋﻢ إﺣﺪى اﻟﻔﺮﺿـﻴﺎت اﻷﺳﺎﺳـﻴﺔ واﺳـﻌﺔ اﻻﻧﺘﺸﺎر ﰲ ﻋﻠﻢ ﺗﺸﻜﻞ اﻟﻜﻮاﻛﺐ ﻛﻤـﺎ ﻳﻔـﺘﺢ ﻣﺴﺎراً ﺟﺪﻳﺪاً ﻟﻔﻬﻢ ﻛﻴﻔﻴـﺔ ﻧﺸـﺄة اﻟﻜﻮاﻛـﺐ اﻟﺨﺎرﺟﻴﺔ وﺗﻄﻮرﻫﺎ . وﻗﺎل ﻛﺮﻳﺲ دﻳﻔﻴﺲ ﻣﺪﻳﺮ ﺑﺮ ﻧﺎﻣﺞ ا ﺆﺳﺴـﺔ اﻟﻮﻃﻨﻴﺔ اﻷﻣﺮﻳﻜﻴﺔ ﻟﻠﻌﻠﻮم ﰲ ﻣﺨﺘﱪ ﻧﻮﻳﺮﻻب : » ﺗُﻈﻬ ـﺮ ﻫــﺬه اﻻﻛﺘﺸـﺎﻓﺎت ﻗــﺪرة ﻣﺮﺻـﺪ ﺟﻴﻤﻴﻨﻲ ﻋﲆ ﻣﺴـﺎﻋﺪﺗﻨﺎ ﰲ ﻓﻬـﻢ ﺧﺼـﺎﺋﺺ ا ﺠﻤﻮﻋﺔ ا ﺘﻨﻮﻋـﺔ وا ﺬﻫﻠـﺔ ﻣـﻦ اﻟﻜﻮاﻛـﺐ اﻟﺨﺎرﺟﻴﺔ ا ﻮﺟﻮدة ﰲ ﺟﻮارﻧﺎ اﻟﻜﻮﻧﻲ . وﻣﺜﻞ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ ﻻ ﻳﻤﻜـﻦ ﺗﺤﻘﻴﻘﻬـﺎ إﻻ ﺑﻔﻀــﻞ اﻷدوات ا ﺘﻄــﻮرة ا ﻟﺘــﻲ ﻳﻤﺘﻠﻜﻬــﺎ ا ﺮﺻﺪ . « راﺑﻂ ﻛﻴﻤﻴﺎﺋﻲ ﺑ اﻟﻨﺠﻢ وﻛﻮاﻛﺒـﻪ ﻳﻌﺘﻘﺪ اﻟﻌﻠﻤﺎء أن اﻟﻜﻮاﻛﺐ اﻟﻌﻤﻼﻗﺔ اﻟﺤـﺎرة ﻣﺜـﻞ WASP-189 b ﺗﻤﺘﻠـﻚ أﻏﻠﻔـﺔ ﻏﺎزﻳـﺔ ﺗﺄﺛﺮت ﻛﻴﻤﻴﺎﺋﻴﺎً ﺑﺎﻟﻘﺮص اﻟﻜﻮﻛﺒﻲ اﻷوﱄ اﻟﺬي ﺗﺸﻜﻠﺖ ﻣﻨﻪ . وﺗﻔﱰض اﻟﻨﻤﺎذج اﻟﺤﺎﻟﻴﺔ أن ﻧﺴﺒﺔ اﻟﻌﻨـﺎﴏ اﻟﺼﺨﺮﻳﺔ داﺧﻞ ﻫﺬا اﻟﻘﺮص ﻳﺠﺐ أن ﺗﻜـﻮن ﻣ ﻤﺎﺛﻠﺔ ﻟﻠﻨﺴﺐ ا ﻮﺟﻮدة ﰲ اﻟﻨﺠﻢ ا ﻀﻴﻒ ﻷن ﻛﻠﻴﻬﻤﺎ ﻧﺸﺄ ﻣﻦ اﻟﺴﺤﺎﺑﺔ اﻷوﻟﻴﺔ ﻧﻔﺴﻬﺎ ﻣـﻦ اﻟﻐﺎز واﻟﻐﺒﺎر وﻗﺪ اﺳﺘُﺨﺪﻣﺖ ﻫﺬه اﻟﻔﺮﺿـﻴﺔ ﻟﻌﻘﻮد ﰲ ﻧﻤﺬﺟﺔ ﺗﺮﻛﻴﺐ اﻟﻜﻮاﻛﺐ اﻟﺼـﺨﺮﻳﺔ ﺧﺎرج اﻟﻨﻈﺎم اﻟﺸ ـ ﻤﴘ إﻻ أﻧﻬﺎ ﻛﺎﻧﺖ ﺗﺴﺘﻨﺪ ﺑﺸﻜﻞ أﺳﺎﳼ إﱃ اﻷدﻟﺔ ا ﺴﺘﻤﺪة ﻣﻦ اﻟﻨﻈﺎم اﻟﺸ ـ ﻤﴘ ﻓﻘﻂ وﻟﻢ ﺗُﺨ ﺘﱪ ﻣﺒﺎﴍة ﰲ أﻧﻈﻤﺔ ﻛﻮﻛﺒﻴﺔ أﺧﺮى . أﻣﺎ اﻵن ﻓﻘﺪ وﻓﺮ اﻟﻜﻮﻛﺐ WASP-189 b أول دﻟﻴﻞ رﺻـﺪي ﻣﺒـﺎﴍ ﻳـﺪﻋﻢ ﻫـﺬه اﻟﻌﻼﻗـﺔ اﻟﻜﻴﻤﻴﺎﺋﻴ ـﺔ ﺑ ـ اﻟ ـﻨﺠﻢ وﻛﻮاﻛﺒــﻪ . وﻗ ـﺎل »: ﺳﺎﻧﺸﻴﺰ ﻳﻮﻓﺮ ﻟﻨﺎ اﻟﻜﻮﻛـﺐ WASP-18 b ﻣﺮﺟﻌﺎً رﺻﺪﻳﺎً ﻣﻬﻤﺎً ﻟﻔﻬﻢ ﺗﺸـﻜﻞ اﻟﻜﻮاﻛـﺐ اﻟﺼﺨﺮﻳﺔ، ﻷﻧﻪ ﻳﻘﺪم ﻛﻤﻴـﺔ ﻗﺎﺑﻠـﺔ ﻟﻠﻘﻴـﺎس ﺗﺆﻛﺪ اﻟﺘﺸﺎﺑﻪ ا ﻔﱰض ﺑ ﺗﺮﻛﻴـﺐ اﻟﻨﺠـﻮم وﻧﺴﺐ ا ﻮاد اﻟﺼﺨﺮﻳﺔ ا ﺴﺘﺨﺪﻣﺔ ﰲ ﺗﻜـﻮﻳﻦ اﻟﻜﻮاﻛﺐ ﺣﻮﻟﻬـﺎ ـ ﻻ ﺗـ و ﻘﺘﴫ أﻫﻤﻴـﺔ ﻫـﺬه اﻟﻔﺮﺿﻴﺔ ﻋﲆ دراﺳﺔ ﻧﺸﺄة اﻟﻜﻮاﻛﺐ ﻓﺤﺴﺐ ﺑﻞ ﺗﻤﺘﺪ أﻳﻀﺎً إﱃ ﻋﻠﻢ اﻷﺣﻴﺎء اﻟﻔﻠﻜـﻲ اﻟـﺬي ﻳﻬﺘﻢ ﺑﺪراﺳﺔ اﻟﺒﻴﺌﺎت اﻟﻘﺎﺑﻠﺔ ﻟﻠﺤﻴـﺎة داﺧـﻞ ــــــــــــــــــــــــــــــ ـــــــ