Free Astronomy Magazine November-December 2025 ARABIC VERSION

sion of the Kuiper Belt, an icy ring of debris that encircles our Solar System.Theresultswerepublished inthe MonthlyNoticesoftheRoyal Astronomical Society . An interna- tional team of astronomers were able to determine this carnage by analysing the chemical composi- tion of the doomed object as its piecesfellontothewhitedwarf.In particular, they detected “vola- tiles” (substances with low boiling points) including carbon, sulphur, nitrogen, and a high oxygen con- tent that suggests the strong pres- ence of water. “We were sur- prised,” saidSnehalataSahuof the University of Warwick in the United Kingdom. Sahu led the data analysis of a Hubble survey ofwhite dwarfs. “We did not expect to find water or other icy content. This is because the comets and KuiperBelt-likeobjectsarethrown out of their planetary systems early, as their stars evolve into whitedwarfs.Buthere,wearede- tecting this very volatile-rich ma- terial. This is surprising for as- tronomers studying white dwarfsaswellasexoplanets,planetso ut- sideourSolarSystem.” UsingHub- ble’sCosmicOriginsSpectrograph, theteamfoundthatthefragments were composed of nearly two thirdswaterice.Thefactthatthey detected so much ice meant that thepieceswerepartofaverymas- siveobjectthatformedfaroutin the star system’s icy Kuiper Belt analogue. Using Hubble data, sci- entistscalculatedthattheobject wasbiggerthantypicalcometsand may be a fragment of an exo- Pluto. They also detected a large fraction of nitrogen − the highest ever detected in white dwarf de- brissystems. “WeknowthatPluto’s surface is covered with nitrogen ices,” saidSahu. “Wethinkthatthe whitedwarfaccretedfragmentsof the crust and mantle of a dwarf planet.” Accretion of these vola- tile-richobjectsbywhitedwarfsis very difficult to detect in visible light.Thesevolatileelementscan only be detected with Hubble’s uniqueultravioletlightsensitivity. In optical light, the white dwarf would appear ordinary. About 260 light-years away, the whitedwarfisarelativelyclose cosmic neighbor. In the past, whenit was a Sun-like star, it would have been expected to host planets andan analogue to our Kuiper Belt. Bil- lions of years from now, when ourSunburnsoutandcollapsestoa whitedwarf,KuiperBeltobjects might be attracted by the immense gravityofthestellarremnant. “Theseplanetesimalswillthenbe disrupted and accreted,” said Sahu. “If an alien observer looks into our Solar System in the far future, they might see the same kind of remains weseetodayaroundthiswhitedwarf.” The team hopes to use the NASA/ESA/CSAJamesWebbSpace Telescope to detect molecular fea- turesofvolatilessuchaswatervapour and carbonates by observing thiswhitedwarfininfraredlight. By further studying white dwarfs,scientists can better understand the frequency and composition of these volatile- richaccretionevents.Sahuis also following the recent discoveryof the interstellar comet 3I/ATLAS. Sheiseagertolearnitschemical composition, especially its fractionofwater. “Thesetypesofstudie swill helpuslearnmoreaboutplanetfor- mation.Theycanalsohelpusunder- standhowwaterisdeliveredto rockyplanets,” saidSahu.BorisGän- sicke, of the University of Warwick and a visitor at Spain’s Instituto de AstrofisicadeCanarias,wastheprin- cipal investigator of the Hubble pro- gram that led to this discovery. “We observedover500whitedwarfswith Hubble. We’ve already learned so much about the building blocks and fragments of planets, but I’ve beenabsolutelythrilledthatwe now identified a system that resem- bles the objects in the frigid outer edgesofoursolarsystem,” said Gänsicke. “Measuring the composi- tion of an exo-Pluto is an important contributiontowardourunder- standing of the formation and evo- lutionofthesebodies.”     NOVEMBER-DECEMBER2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 25 ﻣﺰﻗﺖ ﺟﺮﻣﺎً ﺟﻠﻴﺪﻳﺎً ﻣﻦ ﺑﻘﺎﻳﺎ ﻧ ﻛﻮﻛﺒﻲ ﻈﺎم ﺰام ﻛﺎﻳﱪ ﺣ ﻳﺸﺒﻪ اﻟ وﻫﻮ اﻟ ﺤﻠﻘﺔ ﺠﻠﻴﺪﻳﺔ ﻣﻦ اﻟﺤﻄ ـﺎم ﺗﺤ ـﻴﻂ اﻟﺘــﻲ ﺗﺤــﻴﻂ ﺑ ﻨﻈﺎﻣﻨ ـﺎ اﻟﺸ ﻤﴘـ وﻗﺪ ﻧـ ﴩت اﻟﻨﺘﺎﺋﺞ ـﰲ اﻟ ﻨﴩات اﻟﺸﻬﺮ ﻳﺔ ﻟﻠﺠﻤﻌﻴﺔ اﻟﻔﻠ ﻜﻴﺔ ا ﻠﻜﻴـﺔ . ﺣﻴـﺚ ﺗﻤﻜ ﻦ ﻓﺮﻳﻖ دوﱄ ﻣﻦ اﻟ ﻌﻠﻤـﺎء ﻣـﻦ ﺗﺤﺪﻳـﺪ اﻟﻜﺎرﺛﺔ " ﻫﺬه اﻟﻨﺠﻤﻴﺔ " ﻣﻦ ﺧـﻼل ﺗﺤﻠﻴـﻞ اﻟﱰﻛﻴﺐ اﻟﻜﻴﻤﻴﺎﺋﻲ ﻟﻠﻤﻮاد اﻟﺴـﺎﻗﻄﺔ ﻋـﲆ اﻟﻘﺰم اﻷﺑﻴﺾ وﻛﺸﻒ اﻟﺘﺤﻠﻴﻞ ﻋـﻦ وﺟـﻮد ﻣــﻮاد ﻣﺘﻄــﺎﻳﺮة ) ذات درﺟــﺎت ﻏﻠﻴــﺎن ﻣﻨﺨﻔﻀـﺔ ( ﺗﺸـﻤﻞ اﻟﻜﺮﺑ ـﻮن واﻟﻜﱪﻳــﺖ واﻟﻨ ﻴﱰوﺟ وﻧﺴﺒﺔ ﻋﺎﻟﻴﺔ ﻣـﻦ اﻷﻛﺴـﺠ ﻣﻤﺎ ﻳﺸ إﱃ وﺟـﻮد ﻗـﻮي ﻟﻠﻤـﺎء . وﻗﺎﻟـﺖ ﺳﻨﻬﺎﻻﺗﺎ ﺳـﺎﻫﻮ ﻣـﻦ ﺟﺎﻣﻌـﺔ واروﻳـﻚ ﰲ ا ﻤﻠﻜﺔ ا ﺘﺤﺪة اﻟﺘﻲ تﻗﺎد ﺗﺤﻠﻴـﻞ ﺑﻴﺎﻧـﺎت ﻣﺴﺢ ﻫﺎﺑﻞ ﻟﻸﻗﺰام اﻟﺒﻴﻀﺎء ": ﻟﻘﺪ ﻓﻮﺟﺌﻨـﺎ و ﺗﻤﺎﻣﺎً ﻟﻢ ﻧﺘﻮﻗﻊ اﻟﻌﺜـﻮ ر ﻋـﲆ ا ـ ﺎء أو أي ﻣﻜﻮﻧــﺎت ﺔ ﺟﻠﻴﺪﻳــ أﺧــﺮى نﻷ ا ــﺬﻧﺒﺎت واﻷﺟﺮام اﻟﺸﺒﻴﻬﺔ ﺑﺤﺰام ﻛـﺎﻳﱪ ﻋـﺎدة ﻣـﺎ ﺗ أ ﻄﺮد ﻣﻦ ﻧﻈﻤﺘﻬﺎ اﻟﻜﻮﻛﺒﻴـﺔ ﻣ ﺣـ اً ﺒﻜـﺮ ﺗﺘﺤﻮل ﻧﺠﻮﻣﻬﺎ إﱃ أﻗﺰام ﺑﻴﻀﺎء وﻣﻊ ذﻟـﻚ ﻓﻘـﺪ اﻛﺘﺸـﻔﻨﺎ ﻣــﺎدة ﻏﻨﻴــﺔ ﺟـﺪ اً ﺑـﺎ ﻮاد ا ﺘﻄﺎﻳﺮة وﻫﻮ ﻣﺎ ﻳﺸـﻜﻞ ﻣﻔﺎﺟـﺄة ﻛﺒـ ة ﻟﻌﻠﻤـﺎء اﻟﻔﻠـﻚ ا ﻬﺘﻤـ ﺑﺪراﺳـﺔ اﻷﻗـﺰام اﻟﺒﻴﻀـﺎء و اﻟﻜﻮاﻛــﺐ اﻟﺨﺎرﺟﻴـﺔ ﻋـﲆ ﺣـﺪ .ﺳﻮاء وﺑﺎﺳﺘﺨﺪام ﻣﻄﻴﺎف اﻷﺻﻮل اﻟﻜﻮﻧ ﻴﺔ اﻟﺘﺎﺑﻊ ﻟﺘﻠﺴـﻜﻮب ﻫﺎﺑـﻞ وﺟـﺪ اﻟﻔﺮﻳـﻖ أن اﻟﻜﻮﻧ ﻴﺔ ﻋﲆ ﻣﺘﻦ ﺗﻠﺴـﻜﻮب ﻫﺎﺑـﻞ ﺗﻤﻜـﻦ ﻓﺮﻳﻖ اﻟﻌﻠﻤـﺎء ﻣـﻦ اﻛﺘﺸـﺎف أن اﻟﺸـﻈﺎﻳﺎ اﻟﺴﺎﻗ ﺔ ﻄ ﺗﺘﻜﻮن ﻠﺜـﺜاﻟ ﺑﻨﺤﻮ ﻣـﻦ ﺟﻠﻴـﺪ . ﻣﺎﺋﻲ وﻳﻌﺪ ﻫﺬا اﻟﻘﺪر اﻟﻜﺒ ﻣـﻦ اﻟ ﺠﻠﻴـﺪ دﻟﻴﻼً ﻋﲆ أن ﺗﻠﻚ اﻟﻘﻄﻊ ﻛﺎﻧـﺖ ﺟـﺰء اً ﻣـﻦ ﺟﺮم ﺟﺪاً ﺿﺨﻢ ﺗﺸﻜﻞ ﰲ ا ﻨﺎﻃﻖ اﻟﺨﺎرﺟﻴﺔ اﻟﺒﺎردة ﻣﻦ اﻟﻨﻈﺎم اﻟﻨﺠﻤﻲ ﰲ ﻣﻨﻄﻘﺔ ﺗﺸﺒﻪ ﺣﺰ ام ﻛﺎﻳﱪ اﻟﺠﻠﻴﺪي ﰲ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤـ .ﴘـ وﺑﺘﺤﻠﻴـﻞ ﺑﻴﺎﻧـﺎت ﺗﻠﺴـﻜﻮب ﻫﺎﺑـﻞ وﺟـﺪ اﻟﻌﻠﻤﺎء أن ﻫﺬا اﻟﺠﺮم ﻛﺎن أﻛﱪ ﻣﻦ ا ﺬﻧﺒﺎت اﻟ ﺘﻘﻠﻴﺪﻳﺔ وﻗﺪ ﻳﻜﻮن ﺟﺰء ا ﻣﻦ ﻛﻮﻛﺐ ﻗـﺰم ﺒﻠﻮﺗـﻮ ﺑ ﻪﻴﺷﺒ . ﻛﻤـﺎ رﺻـﺪ اﻟﻔﺮﻳـﻖ ﻧﺴـﺒﺔ ﻣﺮﺗﻔﻌﺔ ﺟﺪاً ﻣﻦ اﻟﻨﻴﱰوﺟـ وﻫـﻲ أﻋـﲆ ﻧﺴﺒﺔ ﺗﻜﺘﺸﻒ ن ﺣﺘﻰ اﻵ ﰲ أﻧﻈﻤـﺔ ﺣﻄـﺎم ا ﺤﻴﻄﺔ ﺑ ﺎﻷﻗﺰام اﻟﺒﻴﻀﺎء . ﺖﻗﺎﻟـ و : " ﺳـﺎﻫﻮ ﻧﻌﻠـﻢ أن ﺳـﻄ ﺢ ﺑﻠﻮﺗـﻮ ﻣﻐﻄﻰ ﺑﺠﻠﻴﺪ اﻟﻨﻴﱰوﺟ و ﻧﻌﺘﻘﺪ أن اﻟﻘﺰم اﻷﺑﻴﺾ ﻗﺪ ﺟﻤﻊ ﺑﺎﻟﻔﻌﻞ ﴩة ـ ﺷﻈﺎﻳﺎ ﻣﻦ ﻗ ووﺷﺎح ﻛﻮﻛﺐ ﻗﺰم ﺷـﺒﻴﻪ ﺑﺒﻠﻮﺗـﻮ ." وﻳﻌـﺪ رﺻـﺪ ﻣﺜـﻞ ﻫـﺬه اﻷﺟـﺮام اﻟﻐﻨﻴـﺔ ﺑـﺎ ﻮاد ا ﺘﻄﺎﻳﺮة أﻣـﺮاً ﺑـﺎﻟﻎ اﻟﺼـﻌﻮﺑﺔ ﰲ اﻟﻀـﻮء ا ﺮﺋﻲ إذ ﺗﻈﻬـﺮ ا ﻷﻗـﺰام اﻟﺒﻴﻀـﺎء ﰲ ﺗﻠـﻚ اﻷ ﻃـﻮال ا ﻮﺟﻴــﺔ ﻋﺎدﻳـﺔ ﺗﻤﺎﻣـﺎً . أن ﻏـ اﻟ ﺤﺴﺎﺳـﻴﺔ اﻟﻔﺎﺋﻘـﺔ ﻟ ﺘﻠﺴـﻜﻮب ﰲ ﻫﺎﺑـﻞ ﻧﻄﺎق ا ﻷﺷـﻌﺔ ﻓـﻮق اﻟﺒﻨﻔﺴـﺠﻴﺔ ﻣﻜﻨـﺖ اﻟﻌﻠﻤـﺎء ﻣـﻦ ﺗﺤﺪﻳـﺪ ﺑﺼـﻤﺎت اﻟﻌﻨـﺎﴏ ـــــــــــــــــــــــــــــــــ ـــ ﻣﻜﻨﺖ اﻟﻌﻠﻤﺎء ﻣﻦ ﺗﺤﺪﻳﺪ ﺑﺼﻤﺎت اﻟﻌﻨﺎﴏ ا ﺘﻄﺎﻳﺮة اﻟﺘﻲ ﻻ ﻳﻤﻜﻦ اﻛﺘﺸﺎﻓﻬﺎ ﺑﺎﻟﻮﺳﺎﺋﻞ اﻟﺘﻘﻠﻴﺪﻳﺔ . ﻳﻌﺘﻘﺪ أن ﻫﺬا اﻟﻘﺰم اﻷﺑﻴﺾ ﻗـﺪ اﺳﺘﻀﺎف ﰲ ﻣﺎﺿﻴﺔ وﻧﻈ ﻛﻮاﻛﺐ اً ﺟﻠﻴﺪﻳﺎً ﻟﺤﺰام ﻛﺎﻳﱪ . ﺑﻌﺪ ﻣﻠﻴﺎرات اﻟﺴﻨ ﻣـﻦ اﻵن ﻋﻨﺪﻣﺎ ﺗﺴﺘﻨﻔﺪ اﻟﺸـﻤﺲ وﻗﻮدﻫـﺎ اﻟﻨـﻮوي ﻮل ﺘﺤوﺗ إﱃ ﻗﺰم أﺑﻴﺾ ﻗﺪ ﺗﻨﺠـﺬب أﺟـﺮام ﺣﺰام ﻛﺎﻳﱪ ﺑﻔﻌﻞ اﻟﺠﺎذﺑﻴﺔ اﻟﻬﺎﺋﻠﺔ ﻟﻠﺒﻘﺎﻳـﺎ اﻟﻨﺠﻤﻴﺔ . ﺖﻗﺎﻟو : " ﺳﺎﻫﻮ ﺣﻴﻨﻬﺎ ﺳﻨﺸﻬﺪ ﺗ ﻔﻜﻚ ﻫﺬه اﻷﺟﺮام اﻟﻜﻮﻛﺒﻴﺔ اﻷوﻟﻴﺔ ا ﺼـﻐﺮة ﻟ ﺘـﱰاﻛﻢ ﺑﻌﺪ ذﻟﻚ ﻋﲆ اﻟﻘﺰم اﻷ و ﺑﻴﺾ إذا ﻧﻈﺮ ﻣﺮاﻗﺐ ﻓﻀــﺎﺋﻲ إﱃ ﻧ ﻈﺎﻣﻨــﺎ اﻟﺸﻤــ ذﻟــﻚ ﴘﰲ ـ ا ﺴﺘﻘﺒﻞ اﻟﺒﻌﻴﺪ ﻓﻘﺪ ﻳـﺮى ا ﺸـﻬﺪ ﻪ ﻧﻔﺴـ اﻟـﺬي ﻧﺮﺻـﺪه اﻟﻴـﻮم ﺣـﻮل ﻫـﺬا اﻟﻘ ـﺰم اﻷﺑﻴﺾ ." ﻳﺄﻣﻞ اﻟﻔﺮﻳﻖ ﰲ اﺳﺘﺨﺪام ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳﺎ ووﻛﺎﻟـﺔ اﻟﻔ ﻀﺎء اﻷوروﺑﻴﺔ ووﻛﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪﻳـﺔ ﻣﻦ اﺟﻞ اﻟﻜﺸﻒ ﻋﻦ اﻟﺒﺼـﻤﺎت اﻟﺠﺰﻳﺌﻴـﺔ ﻟﻠﻤﻮاد ا ﺘﻄﺎﻳﺮة ﻣﺜﻞ ﺑﺨﺎر ا ﺎء واﻟﻜﺮﺑﻮﻧﺎت ﻣﻦ ﺧﻼل ﻣﺮاﻗﺒﺔ اﻟﻐﻼف اﻟﺠﻮي ﻟ ﻬﺬا اﻟﻘﺰم اﻷﺑﻴﺾ ﰲ ﺿﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء . و ﻣﻦ ﺧﻼل دراﺳﺔ اﻷﻗﺰام اﻟﺒﻴﻀﺎء ﺑ ﺼـﻮرة أﻋﻤﻖ ﻳﻤﻜﻦ ﻟﻠﻌﻠﻤﺎء ﻓﻬﻢ و ﻣﻌـﺪل ﺗﻜـﻮﻳﻦ أﺣﺪاث اﻟـﱰاﻛﻢ اﻟﻐ ﻨﻴـﺔ ﺑـﺎ ﻮاد ا ﺘﻄـﺎﻳﺮة ﺑﺸــﻜﻞ أدق . ﻛﻤــﺎ أﺷــﺎرت إﱃ ﺳــﺎﻫﻮ اﻻﻛﺘﺸـﺎف اﻷﺧـ ﻟﻠﻤـﺬﻧﺐ ﺑـ اﻟﻨﺠـﻮم 3I/ أﻃﻠـﺲ ﻣﻌﺮﺑـﺔ ﻋـﻦ ﺷـﻐﻔﻬﺎ ﻌﺮﻓـﺔ اﻟﱰﻛﻴﺐ اﻟﻜﻴﻤﻴﺎﺋﻲ . وﻗﺎل ﺑﻮرﻳﺲ ﺟﺎﻧﺴﻜﻲ ﻣﻦ ﺟﺎﻣﻌﺔ واروﻳﻚ وزاﺋـﺮ ﰲ ﻣﻌﻬـﺪ ﺟـﺰر اﻟ ﻜﻨـﺎري ﻟﻠﻔﻴﺰﻳـﺎء اﻟﻔﻠﻜﻴﺔ اﻹﺳـﺒﺎﻧﻲ و اﻟﺒﺎﺣـﺚ اﻟﺮﺋﻴـ ـ ﴘ ﰲ ﺑﺮﻧﺎﻣﺞ ﻫﺎﺑﻞ اﻟﺬي ﻗﺎد إﱃ ﻫﺬا اﻻﻛﺘﺸـﺎف : " ﻟﻘﺪ رﺻﺪﻧﺎ أﻛﺜـﺮ ﻣـﻦ 500 ﻗـﺰم أﺑـﻴﺾ ﺑﺎﺳﺘﺨﺪام ﺗﻠﺴﻜﻮب و ﻫﺎﺑﻞ ﺗﻌﻠﻤﻨـﺎ اﻟﻜﺜـ ﺗﻜﻮﻳﻦ ﻋﻦ اﻟﻜﻮاﻛﺐ وﺑﻨﻴﺘﻬﺎ ﻟﻜﻨﻨﻲ اﺷـﻌﺮ ﺑﺴﻌﺎدة ﺑﺎﻟﻐﺔ ﻷﻧﻨﺎ اﻵن ﺎ ﺗﻤﻜﻨ ﻣـﻦ ﺗﺤﺪﻳـﺪ ﻧﻈﺎم ﻧﺠﻤـﻲ ﻳﺸـﺒﻪ اﻷﺟـﺮام ا ﻮﺟـﻮدة ﰲ اﻟﺤــﻮاف اﻟﺨﺎرﺟﻴــﺔ اﻟﺒــﺎردة ﻟﻨﻈﺎﻣﻨــﺎ اﻟﺸ إن و ﻤﴘـ دراﺳـﺔ اﻷﺟـﺮام ا ﺸـﺎﺑﻬﺔ ﻠﻮﺗﻮ ﺒﻟ ﺗﻤﺜـﻞ ﻣﺴـﺎﻫﻤﺔ ﻣﻬﻤـﺔ ﰲ ﻓﻬﻤ ﻨـﺎ ﻟﺘﻜﻮﻳﻦ وﺗﻄـﻮر اﻷ ﻫـﺬه ﺟـﺮام اﻟﺒﻌﻴـﺪ ﰲ ة اﻷﻧﻈﻤﺔ اﻟﻜﻮﻛﺒﻴﺔ . ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 5