Free Astronomy Magazine March-April 2026 ARABIC VERSION

A team using the NASA/ESA Hub- bleSpaceTelescopehasuncov- ered a new type of astronomical object —a starless, gas-rich, dark- matter cloud that is considered a “relic” or remnant of early galaxy formation. Nicknamed “Cloud-9,” this is the first confirmed detection of such an object in the Universe. This image shows the blank field of the surrounding region of Cloud-9, which is 2,000 light-years from Earth. [NASA, ESA. G. Anand(STScI), Vand A. Benitez-Llambay (Univ. of Milan-Bicocca); Image processing: J. DePasquale (STScI)] Scientistshavebeenstudyinghydro- gen clouds near the Milky Way for manyyears,andthesecloudstendto be much bigger and irregular than Cloud-9. Compared with other ob- served clouds, Cloud-9 is smaller, morecompact,andhighlyspherical, making it look very different from other clouds. The core of this object is composed of neutral hydrogen andisabout4,900light-yearsindi- ameter.ThehydrogengasinCloud-9 is approximately 1 million times themassoftheSun.Butifthepres- sureofthegasisbalancingthegrav- ityofthedarkmattercloud,whichit appears to be, Cloud-9 must be heavilydominatedbydarkmatter,at about 5 billion solar masses. Cloud-9 is an example of the structures and the mysteries that don’t involve stars. Just looking at stars doesn’t give the full picture. Studying the gas and dark matter helps provide a more complete un- derstanding of what’s going on in these systems that otherwise would- n’t be known. Observationally, iden- tifying these failed galaxies is challenging because nearby objects outshinethem.Suchsystemsarealso vulnerable to environmental effects like ram-pressure stripping, which can remove gas as the cloud moves through intergalactic space. These factorsfurtherreducetheirexpected numbers. The starless relic was dis- covered three years ago as part of a radio survey by the Five-hundred- meter Aperture Spherical Telescope (FAST) in Guizhou, China, a finding later confirmed by the Green Bank Telescope and the Very Large Array facilities in the United States. But only with Hubble could researchers definitivelydeterminethatthefailed galaxycontainsnostars.Cloud-9was simplynamedsequentially,having been the ninth gas cloud identified on the outskirts of a nearby spiral galaxy,Messier94(M94).Thecloud isclosetoM94andappearstohave a physical association with the galaxy. High-resolution radio data showsslightgasdistortions,possibly indicating interaction between the cloud and galaxy. The cloud may eventually form a galaxy in the fu- ture,provideditgrowsmoremassive —althoughhowthatwouldoccuris under speculation. If it were much bigger,say,morethan5billiontimes the mass of our Sun, it would have collapsed, formed stars, and become agalaxythatwouldbenodifferent than any other galaxy we see. If it were much smaller than that, the gas could have been dispersed and ionizedandtherewouldn’tbemuch left.Butit’sinasweetspotwhereit couldremainasaRELHIC.Thelackof starsinthisobjectprovidesaunique windowintotheintrinsicproperties ofdarkmatterclouds.Therarityof suchobjectsandthepotentialforfu- turesurveysisexpectedtoenhance the discovery of more of these “failedgalaxies”or“relics,”result- ingininsightsintotheearlyuniverse andthephysicsofdarkmatter. ■ MARCH-APRIL2026 ﺗﻤﻜﻦ ﻓﺮﻖ ﺎﺳﺘﺨﺪام ﺗﻠﺴ ﻮب ﻣﻦ اﻟ ﺎﺣﺜ ــــﺪ ﻣــــﻦ ﻫﺎﺑــــﻞ اﻟﻔﻀــــﺎﺋﻲﻣــــﻦ اﻛﺘﺸــــﺎف ﻧــــﻮع ﺟﺪ ـــــﺔ اﻷﺟــــﺮام اﻟﻔﻠﻜ وﻫــــﻲ ــــﺔ ﺎﻟﻐـــــﺎز ﺳـــــﺤﺎ ﺔ ﻏﻨ ــــــﺔ ﻣــــــﻦ اﻟﻨﺠــــــﻮم وﻳﻬــــــ ﻤﻦ ﻋﻠﻴﻬــــــﺎ اﻟﻤــــــﺎدة ﺧﺎﻟ اﻟﻤﻈﻠﻤـــــﺔ وﺗﻌـــــﺪ ـــــﺎ ﻘﺎ ﻣـــــﻦ اﻟﻤﺮاﺣـــــﻞ اﻟﻤ ﻜـــــﺮة ﻟﺘﺸ ﻞ اﻟﻤﺠﺮات و ﻄﻠﻖ ﻋﻠـﻰﻫـﺬا اﻟـ ﺮمﺠـ ﻟﻘـﺐ ” اﻟﺴـﺤﺎ ﺔ "9- ﻮوﻫــ أول رﺻــﺪ ﻣﺆﻛــﺪ ﻟﻤﺜــﻞ ﻫــﺬا اﻟﻨـــﻮع ﻣـــﻦ اﻷ ﺟـــﺮام ـــﻮن ﻓـــﻲ اﻟ ﺗ. ﻈﻬـــﺮ اﻟﺼـــﻮرة ـاﻟ ـ ﺤﻘﻞ اﻟ ﺨﺎﻟﻲ ﺣﻮل ﻣﻨﻄﻘﺔ اﻟﺴﺤﺎ ﺔ 9- واﻟ ﺗ ﻌﺪ 2000 ﺳﻨﺔ ﺿﻮﺋ ﺔ ﻋﻦ اﻷرض . [NASA, ESA. G. Anand (STScI), and A. Benitez-Llambay (Univ. of Milan-Bicocca); Image processing: J. DePasquale (STScI)] ﻳﺪرس اﻟﻌﻠﻤﺎء ﺳﺤﺐ اﻟﻬﻴﺪروﺟ اﻟﻘﺮﻳﺒـﺔ ﻣﻦ ﻣ ﺠﺮة درب اﻟﺘﺒﺎﻧﺔ ﻣﻨﺬ ﺳﻨﻮات ﻃﻮﻳﻠـﺔ وﻋ ﺎدة ﻣﺎ ﺗﻜﻮن ﻫﺬه اﻟﺴﺤﺐ أﻛـﱪ ﺣﺠﻤـ ﺎ ﺮ وأﻛﺜ اﻧﺘﻈﺎﻣ ﺎً ﻣﻦ اﻟﺴـﺤﺎﺑﺔ 9- ﺑﺎو ﻘﺎرﻧـﺔ ﻣﻊ اﻟﺴﺤﺐ اﻷﺧﺮى ﺗﻌﺪ اﻟﺴﺤﺎﺑﺔ 9- أﺻﻐﺮ و ﺣﺠﻤﺎً أﻛﺜﺮ ﺗﻤﺎﺳﻜ ﺎً وﺷﺪﻳﺪة اﻟﻜﺮو ﻳﺔ ﻣـﺎ ﻳﺠﻌﻞ ﺷﻜﻠﻬﺎ ﻣﺨﺘﻠﻔ ﺎً ﺑﻮﺿـﻮح ﻋـﻦ ﺑﻘﻴـﺔ اﻟﺴﺤﺐ . ﻳﺘﻜﻮن ﺰ ﻣﺮﻛـ ﻫـﺬا اﻟﺠﺴـﻢ ﻣـﻦ اﻟﻬﻴـﺪروﺟ ا ﺤﺎﻳـ ﺪ وﻳﺒﻠـﻎ ﻗﻄـﺮه ﻧﺤـﻮ 4900 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ وﺗﺒﻠــﻎ ﻛﺘﻠــﺔ ﻏــﺎز اﻟﻬﻴــﺪروﺟ ﰲ ا ﻟﺴــﺤﺎﺑﺔ 9- ﻣـﺎ ﻳﻘـﺎرب ﻣﻠﻴﻮن ﺿﻌﻒ ﻛﺘﻠﺔ اﻟﺸﻤﺲ ﻟﻜـﻦ إذا ﻛـﺎن ﺿﻐﻂ اﻟﻐﺎز ﻳﻮازن ﺟﺎذﺑﻴﺔ ﺳـﺤﺎﺑﺔ ا ـﺎدة ا ﻈﻠﻤﺔ وﻫﻮ ﻣـﺎ ﺗﺸـ إﻟﻴـﻪ اﻷدﻟـﺔ ﻓـﺈن ﻳﺠﺐ أن ﺗﻜﻮن ﻣﻬﻴﻤﻨًـﺎ ﻋﻠﻴﻬـﺎ اﻟ ﺴﺤﺎﺑﺔ 9- ﻳﺠﺐ أن ﺗﻜﻮن ﻣﻬﻴﻤﻨـﺎً ﻋﻠﻴﻬـﺎ ﺑﺸﺪة ﻣﻦ ﻗﺒﻞ ا ﺎدة ا ﻈﻠﻤﺔ، ﺑﻜﺘﻠﺔ ﺗﻘـﺎرب ﺧﻤﺴـﺔ ﻣﻠﻴـﺎرات ﻛﺘﻠـﺔ ﺷﻤﺴـﻴﺔ . ﺗﻤﺜـﻞ ا ﻟﺴـﺤﺎﺑﺔ 9- ﻣﺜ ـﺎﻻً ﻋــﲆ اﻟﺒﻨ ـﻰ اﻟﻜﻮ ﻧﻴ ـﺔ واﻷﻟﻐﺎز اﻟﺘﻲ ﻻ ﺗﺘﻀﻤﻦ ﻧﺠﻮﻣـ ﺎً ﻓﺎﻻﻛﺘﻔـﺎء ﺑﺮﺻﺪ اﻟﻨﺠﻮم ﻻ ﻳﻤﻨﺢ اﻟﺼﻮرة اﻟﻜﺎﻣﻠﺔ . إن درا ﺳﺔ اﻟﻐﺎز وا ﺎدة ا ﻈﻠﻤﺔ ﺗﻮﻓّﺮ ﻓﻬﻤـ ﺎً أﺷﻤﻞ ﺎ ﻳﺤﺪث ﰲ ﻫﺬه اﻷﻧﻈﻤﺔ اﻟﺘﻲ ﻛﺎﻧﺖ ﺳﺘﺒﻘﻰ ﻣﺠﻬﻮﻟـﺔ ﻟـﻮﻻ ذﻟـﻚ . رﺻـﺪ ﻫـﺬه " ا ﺠﺮات ﻏ ا ﻜﻮﻧﺔ ﻟﻠﻨﺠﻮم " ﻳﻌـﺪ ﺗﺤـﺪﻳ ﺎً ﺎً رﺻﺪﻳ ﻷن اﻷﺟ ﺴﺎم اﻟﻘﺮﻳﺒﺔ اﻷﻛﺜﺮ ﺳﻄﻮﻋ ﺎً ﺗﻄﻐﻰ ﻋﻠﻴﻬﺎ . ﻛﻤﺎ أن ﻫﺬه اﻷﻧﻈﻤﺔ ﻋﺮﺿـﺔ ﻟﺘﺄﺛ ات ﺑﻴﺌﻴﺔ ﻣﺜﻞ اﻟﺘﺠﺮﻳﺪ ﺑﻀﻐﻂ اﻟﺤﺮﻛﺔ ﺣﻴﺚ ﻳﻤﻜـﻦ إزاﻟـﺔ اﻟﻐـﺎز ﻋﻨـﺪﻣﺎ ﺗﺘ ﺤـﺮك اﻟﺴﺤﺎﺑﺔ ﻋﱪ اﻟﻮﺳـﻂ ﺑـ ا ﺠـﺮ . ي ﻫـﺬه اﻟﻌﻮاﻣﻞ ﺗﻘﻠﻞ ﻣ ﻦ اﻟﻌﺪد ا ﺘﻮﻗﻊ ﺜـﻞ ﻫـﺬه اﻷﺟ . ﺮام اﻛﺘُﺸﻔﺖ ﻫﺬه اﻟﺒﻘﺎﻳﺎ اﻟﺨﺎﻟﻴﺔ ﻣـﻦ اﻟﻨﺠﻮم ﻗﺒﻞ ﺛـﻼث ﺳـﻨﻮات ﺿـﻤﻦ ﻣﺴـﺢ رادﻳــﻮي أﺟــﺮاه ﺗﻠﺴ ـﻜﻮب ) ( ﻓﺎﺳــﺖ ذي اﻟﻔﺘﺤﺔ اﻟﻜﺮوﻳﺔ ﺑﻘﻄﺮ 500 ﻣﱰ ﰲ ﻗﻮﻳﺘﺸﻮ ﺑﺎﻟﺼ ﺛﻢ أُﻛﺪ اﻻﻛﺘﺸﺎف ﻻﺣﻘًـﺎ ﺑﻮاﺳـﻄﺔ ﺗﻠﺴﻜﻮب ﻏﺮﻳﻦ ﺑﺎﻧـﻚ وا ﺼـﻔﻮﻓﺔ اﻟﻜﺒـ ة اً ﺟﺪ ﰲ اﻟﻮﻻﻳﺎت ا ﺘﺤـﺪة ﻏـ أن ﺗﻠﺴـﻜﻮب ﻫﺎﺑﻞ وﺣﺪه ﻣﻜ ﻦ اﻟﺒﺎﺣﺜ ﻣﻦ اﻟﺠـﺰم ﺑـﺄن ﻫﺬه ا ﺠﺮة ﻏ ا ﻜﻮﻧﺔ ﻟﻠﻨﺠﻮم ﺗﺨﻠﻮ ﺗﻤﺎﻣﺎً ﻣﻦ اﻟﻨﺠﻮم . ﺳُﻤّﻴﺖ اﻟﺴﺤﺎﺑﺔ 9- ﺑﻬﺬا اﻻﺳـﻢ ﺑﺒﺴـﺎﻃﺔ ﻷﻧﻬـﺎ ﻛﺎﻧـﺖ اﻟﺴـﺤﺎﺑﺔ اﻟﻐﺎزﻳـ ﺔ اﻟﺘﺎﺳﻌﺔ اﻟﺘﻲ ﺟﺮى ﺗﺤﺪﻳﺪﻫﺎ ﻋـﲆ أﻃـﺮاف - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 6 اﻟﺘﺎﺳﻌﺔ اﻟﺘﻲ ﺟﺮى ﺗﺤﺪﻳﺪﻫﺎ ﻋـﲆ أﻃـﺮاف ﻣﺠﺮة ﺣﻠﺰوﻧﻴـﺔ ﻗﺮﻳﺒـﺔ ﻫـﻲ ﻣﺴـﻴﻴﻪ 94 أو (M94) اﺧﺼﺎراً وﻳﺒﺪو أن ﻟﻬـﺎ ارﺗﺒﺎﻃـﺎً . ﺑﻬﺎ ﺎً ﻓﻴﺰﻳﺎﺋﻴ ﺗُﻈﻬـﺮ اﻟﺒﻴﺎﻧـﺎت اﻟﺮادﻳﻮﻳـﺔ ﻋﺎ ﻟﻴـﺔ ا ﻟﺪﻗـﺔ ﺗﺸﻮﻫﺎت ﻃﻔﻴﻔﺔ ﰲ اﻟﻐﺎز ﻗﺪ ﺗﺸ إﱃ وﺟﻮد ﺗﻔﺎﻋﻞ ﺑ اﻟﺴﺤﺎﺑﺔ وا ﺠﺮة ا ﺠﺎورة . ﻗﺪ ﺗﺘﻄﻮر ﻫﺬه اﻟﺴﺤﺎﺑﺔ ﻣﺴﺘﻘ ﺒﻼً إﱃ ﻣﺠﺮة إذا ازدادت ﻛﺘﻠﺘﻬﺎ إﻻ أن ﻛﻴﻔﻴﺔ ﺣﺪوث ذﻟـﻚ ﻻ ﺗﺰال ﻣﻮﺿﻊ ﺑﺤﺚ ودراﺳﺔ ﻓﻠﻮ ﻛﺎﻧﺖ أﻛﱪ ﺑﻜﺜ أي ﺗﺘﺠﺎوز 5 ﻣﻠﻴﺎرات ﻛﺘﻠﺔ ﺷﻤﺴـﻴﺔ ﻻﻧﻬﺎرت وﺷﻜﻠﺖ ﻧﺠﻮﻣﺎً وأﺻـﺒﺤﺖ ﻣﺠـﺮة ﻋﺎدﻳﺔ ﺗﺸﺒﻪ أي ﻣﺠﺮة أﺧﺮى ﻧﺮاﻫﺎ ﰲ اﻟﻜﻮن أﻣﺎ ﻟﻮ ﻛﺎﻧﺖ أﺻـﻐﺮ ﺑﻜﺜـ ﻟﺘﺸـﺘﺖ اﻟﻐـﺎ ز وﺗﺄﻳﻦ وﻟﻢ ﻳﺒﻖ ﻣﻨﻬﺎ ﺳـﻮى اﻟﻘﻠﻴـﻞ ﻟﻜﻨﻬـﺎ ﺗﻘﻊ ﰲ ﻧﻄـﺎق وﺳـﻴﻂ ﻣﺜـﺎﱄ ﻳﺴـﻤﺢ ﻟﻬـﺎ ﺑﺎﻟﺒﻘــﺎء ﻛﺴــﺤﺎﺑﺔ ﻫﻴــﺪر وﺟ ﻣﺤﺎﻳــﺪ ﻣﺤﺪودة ﺑﺈﻋﺎدة اﻟﺘﺄﻳﻦ وﻳﺘﻴﺢ ﻫﺬا اﻟﺘـﻮازن دراﺳﺔ ﺗﺄﺛ ا ﺎدة ا ﻈﻠﻤﺔ ﻋﲆ ﺗﻮ زﻳﻊ اﻟﻐﺎز وﺗﻄﻮر ا ﺠﺮات ﰲ ﻣﺮاﺣﻠﻬﺎ ا ﺒ .ﻜﺮة إن ﻏﻴﺎب اﻟﻨﺠﻮم ﰲ ﻫﺬا اﻟﺠﺮم اﻟﻜﻮﻧﻲ ﻳﻮﻓّﺮ ﻧﺎﻓﺬة ﻟﺪراﺳﺔ اﻟﺨﺼﺎﺋﺺ اﻟﺠﻮﻫﺮﻳﺔ ﻟﺴﺤﺐ ا ﺎدة ا ﻈﻠﻤﺔ . ﻋﲆ اﻟﺮﻏﻢ ﻣـﻦ ﻧـﺪرة ﻫـﺬه اﻷﺟـﺮام ﻓـﺈن اﻷرﺻﺎد ا ﺴﺘﻘﺒﻠﻴﺔ ﻗﺪ ﺗﻜﺸـﻒ ا ﺰﻳـﺪ ﻣـﻦ "ﻫﺬه ا ﺠﺮات ﻏ ا ﺸﻜﻠﺔ ﻟﻠﻨﺠﻮم " وﺗﻘﺪم رؤى ﻣﻬﻤﺔ ﺣﻮل ﻓﻴﺰﻳﺎء ا ﺎدة ا ﻈﻠﻤﺔ .