Free Astronomy Magazine May-June 2026 ARABIC VERSION

MAY-JUNE2026 50 able blobs. Hubble’s images were takenjustamonthafterK1’sclosest approach to the Sun, called perihe- lion. The comet's perihelion was in- sideMercury’sorbit,aboutone-third the distance of the Earth from the Sun. During perihelion, a comet ex- periences its most intense heating and maximum stress. Just past peri- helion is when some long-period comets like K1 tend to fall apart. Beforeitfragmented,K1waslikely abitlargerthananaveragecomet, probablyaround8kilometresacross. The team estimates the comet be- gan to disintegrate eight days be- foreHubbleviewedit.Hubbletook three 20-second images, one on eachdayfrom8Novemberthrough 10 November 2025. As it watched thecomet,oneofK1’ssmallerpie- cesalsobrokeup.BecauseHubble’s sharp vision can distinguish ex- tremelyfinedetails,theteamcould trace the history of the fragments backtowhentheywereonepiece. That allowed them to reconstruct the timeline. But in doing so, they uncoveredamystery:Whywasthere a delay between when the comet brokeupandwhenbrightoutbursts were seen from the ground? When thecometfragmentedandexposed freshice,whydidn’titbrightenal- mostinstantaneously? Theteamhassometheories.Mostof a comet’s brightness is sunlight re- flectedoffofdustgrains.Butwhen acometcracksopen,itrevealspure ice.Maybealayerofdrydustneeds to form over the pure ice and then blow off. Or maybe heat needs to getbelowthesurface,builduppres- sure, and then eject an expanding shell of dust. “Never before has Hubblecaughtafragmentingcomet this close to when it actually fell apart.Mostofthetime,it’safew weeks to a mo nth later. And in this case,wewereabletoseeitjustdays after,” said Noonan. “This is telling us something very important about the physics of what’s happening at thecomet’ssurface.Wemaybesee- ing the timescale it takes to form a substantial dust layer that can then be ejected by the gas.” The team is looking forward to fin- ishing the analysis of the gases to come from the comet. Already, ground-based analysis shows that K1ischemicallyverystrange—itis significantly depleted in carbon, comparedwithothercomets.Spec- troscopicanalysisfromHubble’sSTIS (Space Telescope Imaging Spectro- graph) and COS (Cosmic Origins Spectrograph) instruments is likely torevealmuchmoreaboutthecom- position of K1 and the very origins of our Solar System. The comet K1 is now a collection of fragments about 400 million kilome- ters from Earth. Located in the con- stellation Pisces, it is heading out of the Solar System, not likely to ever return. Astronomers see that long- period comets such as K1 are more likely to fragment than their short- period cousins, such as 67P/Churyu- mov-Gerasimenko that was visitedbyESA’sRosettamission,butitis not known why. Launching towards the end of the decade, ESA’s Comet In- terceptor will be the first mission to visitalong-periodcomet. “Hubble’s chance observation of K1 will help us understand why somelong-period comets split apart and give us a first view of their interi- ors,” saidco- authorProf.ColinSnod- grass of the University of Edinburgh in Scotland and an Interdisciplinary Scientist for the Comet Interceptor mission. “Thesenewresultswillcom- plementthedetailedviewofalong- periodcometthatwewillobtain from Comet Interceptor, as well as helpingastronomerstoselectthe mission’starget.”  https://esahubble.org/vid os/heic2606a/ ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 50 ﻛﻮﻛﺐ ﻋﻄﺎرد ﻋﲆ ﻣﺴﺎﻓﺔ ﺗﻌﺎدل ﻧﺤـﻮ ﺛﻠـﺚ ا ﺴﺎﻓﺔ ﺑ اﻷرض واﻟﺸﻤﺲ . وﺧـﻼل ﻫـﺬه ا ﺮﺣﻠـﺔ ﻳﺘﻌـﺮض ا ـﺬﻧ درﺟـﺎت ﴡـ ﺐ ﻷﻗـ اﻟﺘﺴﺨ واﻹﺟﻬـﺎد وﻏﺎﻟﺒـ ﺎً ﻣـﺎ ﺗﺒـﺪأ ﺑﻌـﺾ ا ـﺬﻧ ﺒﺎت ﻃﻮﻳﻠــﺔ اﻟـﺪورة ﻣﺜـﻞ ا ـﺬﻧ ﺐ K1 ﺑﺎﻟﺘﻔﻜﻚ ﺑﻌﺪ ﺗﺠﺎوز ﻫﺬه اﻟﻨﻘﻄﺔ . ﻗﺒﻞ ﺗﻔﻜﻜﻪ ﻛﺎن ﺣﺠﻢ ا ﺬﻧﺐ K1 أﻛﱪ ﺑﻘﻠﻴﻞ ﻣﻦ ﻣﺘﻮﺳﻂ أﺣﺠﺎم ا ﺬﻧﺒﺎت إذ ﻳﻘﺪ ر ﻗﻄـﺮه ﺑﻨﺤﻮ 8 ﻛﻴﻠﻮﻣﱰات . وﻳﻘﺪ ر اﻟﻔﺮﻳﻖ اﻟﺒﺤﺜﻲ أن ﻋﻤﻠﻴﺔ اﻟﺘﻔﻜﻚ ﺑﺪأت ﻗﺒﻞ ﺛﻤﺎﻧﻴ ﺔ أﻳﺎم ﻣﻦ رﺻﺪ ﺗﻠﺴﻜﻮب ﺎﺑﻞ ﻟﻪ ﻫ . وﻗﺪ اﻟـﺘﻘﻂ ﻫﺎﺑـﻞ ﺛـﻼث ﺻﻮر ﻣﺪة ﻛﻞ ﻣﻨﻬﺎ 20 ﺛﺎﻧﻴﺔ ﰲ اﻷﻳﺎم ﻣـﻦ 8 إﱃ 10 ﻧﻮﻓﻤﱪ 2025 وﺧﻼل ﻋﻤﻠﻴـﺔ اﻟﺮﺻـﺪ ﺗﻔﻜﻜـﺖ إﺣـﺪى اﻟﺸـﻈﺎﻳﺎ اﻟﺼـﻐ ة أﻳﻀـ . ﺎً وﺑﻔﻀﻞ اﻟﺪﻗﺔ اﻟﻌﺎﻟﻴﺔ ﻟ ﺘﻠﺴﻜﻮب ﻫﺎﺑﻞ ﺗﻤﻜﻦ اﻟﻔﺮﻳﻖ ﻣﻦ ﺗﺘ ﺒـﻊ ﺗـﺎرﻳﺦ ﻫـﺬه اﻟﺸـﻈﺎﻳﺎ إﱃ اﻟﻮراء ﻋﻨﺪﻣﺎ ﻛﺎﻧﺖ ﺟﺴ ﻤﺎً واﺣﺪاً ﻣﻤـﺎ أﺗـﺎح إﻋﺎدة ﺑﻨﺎء اﻟﺘﺴﻠﺴﻞ اﻟﺰﻣﻨﻲ ﻟﻌﻤﻠﻴﺔ اﻟﺘﻔﻜـﻚ . إﻻ أن ﻫﺬا اﻟﺘﺤﻠﻴﻞ ﻛﺸﻒ ﻋﻦ ﻟﻐﺰ ﻋﻠﻤﻲ : ﺎذا ﻛﺎن ﻫﻨﺎك ﺗﺄﺧ ﺑ ﻟﺤﻈـﺔ ﺗﻔﻜـﻚ ا ـﺬﻧّﺐ وﻇﻬﻮر اﻻزدﻳﺎد ﰲ ﺳﻄﻮﻋﻪ ﻛﻤـﺎ رُﺻـﺪ ﻣـﻦ وﻇﻬﻮر اﻻزدﻳﺎد ﰲ ﺳﻄﻮﻋﻪ ﻛﻤـﺎ ر ﺻـﺪ ﻣـﻦ اﻷرض؟ و ﺎذا ﻟﻢ ﻳﺰد ﺳﻄﻮﻋﻪ ﻓﻮر اﻧﻜﺸـﺎف اﻟﺠﻠﻴﺪ اﻟﻨﻘﻲ؟ ﻃﺮح اﻟﻔﺮﻳﻖ ﻋـﺪة ﻓﺮﺿـﻴﺎت ﻟﺘ ﻔﺴ ذﻟﻚ . إذ إن ﻣﻌﻈـﻢ ﺳـﻄﻮع ا ـﺬﻧ ﺐ ﻧﺎﺗﺞ ﻋﻦ اﻧﻌﻜﺎسﺿﻮء اﻟﺸﻤﺲ ﻋﲆ ﺣﺒﻴﺒﺎت اﻟﻐﺒﺎر . وﻋﻨﺪ اﻧﻜﺸﺎف اﻟ ﺠﻠﻴﺪ اﻟﻨﻘﻲ ﻗﺪ ﻳﻠـﺰم ﺗﺸﻜﻞ ﻃﺒﻘﺔ ﻣﻦ اﻟﻐﺒﺎر اﻟﺠﺎف ﻓﻮﻗﻪ ﻗﺒﻞ أن ﺗﻄ أو ( ﺗﻘﺬف ) أو رﺑﻤﺎ ﻳﺤﺘﺎج اﻟﺘﺴـﺨ إﱃ اﺧﱰاق اﻟﺴﻄﺢ وﺗﻮﻟﻴﺪ ﺿﻐﻂ داﺧﲇ ﻳﺆدي إﱃ ﻗﺬف ﻏﻼف ﻏﺒﺎري ﻣﺘﻮﺳﻊ . وﻗﺎل ﻧﻮﻧﺎن :» ﻟﻢ ﻳﺴﺒﻖ ﻟ ﺘﻠﺴـﻜﻮب ﻫﺎﺑـﻞ أن رﺻﺪ ﻣﺬﻧّﺒ ﺎً ﻳﺘﻔﻜﻚ ﺑﻬﺬه اﻟﴪﻋﺔ ﺑﻌﺪ ﺣـﺪوث اﻟﺘﻔﻜﻚ اﻟﻔﻌﲇ . ﰲ ﻣﻌﻈ ﻢ اﻟﺤﺎﻻت ﻳﺘﻢ اﻟﺮﺻﺪ ﺑﻌﺪ أﺳﺎﺑﻴ ﻊ أو ﺣﺘﻰ ﺷﻬﺮ أﻣﺎ ﰲ ﻫﺬه اﻟﺤﺎﻟـﺔ ﻓﻘﺪ ﺗﻤﻜﻨـﺎ ﻣـﻦ رﺻـﺪه ﺑﻌـﺪ أﻳـﺎم ﻓﻘـﻂ « . »: وأﺿﺎف ﻫﺬا ﻳﻮﻓﺮ ﻟﻨﺎ ﻣﻌﻠﻮﻣﺎت ﻣﻬﻤﺔ ﺟﺪ اً ﺣﻮل اﻟﻔ ﻴﺰﻳﺎء اﻟﺘﻲ ﺗﺤﺪث ﻋﲆ ﺳﻄﺢ ا ـﺬﻧّﺐ وﻗﺪ ﻧﻜﻮن ﺑﺼﺪد رﺻﺪ ا ﺪة اﻟﺰﻣﻨﻴﺔ اﻟﻼزﻣـﺔ ﻟﺘﺸﻜﻞ ﻃﺒﻘﺔ ﻏﺒﺎرﻳﺔ ﻗﺎﺑﻠـﺔ ﻟﻠﻘـﺬف ﺑﻔﻌـﻞ اﻟﻐﺎزات « . وﻳﺘﻄﻠﻊ اﻟﻔﺮﻳﻖ إﱃ اﺳﺘﻜﻤﺎل ﺗﺤﻠﻴﻞ اﻟﻐﺎزات ا ﻨﺒﻌﺜﺔ ﻣﻦ ا ﺬﻧّﺐ . وﺗﺸ اﻟﺘﺤﻠﻴﻼت اﻟﻐﺎزات ا ﻨﺒﻌﺜﺔ ﻣﻦ ا ﺬﻧّﺐ . وﺗﺸ اﻟﺘﺤﻠﻴﻼت اﻷرﺿـﻴﺔ ﺑﺎ ﻟﻔﻌـﻞ إﱃ أن ا ـﺬﻧﺐ K1 ﻳﺘﻤﺘـﻊ ﺑﱰﻛﻴﺐ ﻛﻴﻤﻴﺎﺋﻲ ﻏ ﻣﻌﺘﺎد إذ ﻳﻈﻬﺮ ﻧﻘﺼـﺎ ﺎً ﻣﻠﺤﻮﻇ ﰲ ﻋﻨﴫ اﻟﻜﺮﺑﻮن ﻣﻘﺎرﻧﺔ ﺑﻤﺬﻧ ﺒﺎت أﺧﺮى . وﻣﻦ ا ﺘﻮﻗـﻊ أن ﺗﻜﺸـﻒ اﻟﺘﺤﻠـﻴﻼت اﻟﻄﻴﻔﻴﺔ ﺑﻮاﺳﻄﺔ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اً ﻣﺰﻳﺪ ﻣـﻦ اﻟﺘﻔﺎﺻﻴﻞ ﺣﻮل ﺗﺮﻛﻴﺐ ا ﺬ ﻧﺐ وأﺻﻮل اﻟﻨﻈﺎم اﻟﺸﻤﴘ . ﺣﺎﻟﻴﺎً أﺻﺒﺢ ا ـﺬﻧّﺐ K1 ﻣﺠﻤﻮﻋـﺔ ﻣ ﻦ اﻟﺸﻈﺎﻳﺎ ﺗﻘﻊ ﻋﲆ ﺑُﻌﺪ ﻧﺤﻮ 400 ﻣﻠﻴـﻮن ﻛﻴﻠﻮﻣﱰ ﻣـﻦ اﻷرض . وﻫـﻮ ﻳﻘـﻊ ﰲ ﻛﻮﻛﺒـﺔ اﻟﺤﻮت وﻳﺘﺠﻪ إﱃ ﺧﺎرج اﻟﻨﻈـﺎم اﻟﺸﻤـ ﴘ ـ وﻣﻦ ﻏ ا ﺮﺟﺢ أن ﻳﻌﻮد ﻣﺠﺪد اً وﻳﺮى ﻋﻠﻤﺎء اﻟﻔﻠﻚ أن ا ﺬ ﻧّﺒﺎت ﻃﻮﻳﻠﺔ اﻟﺪورة ﻣﺜﻞ ا ـﺬﻧﺐ K1 أﻛﺜﺮ ﻋﺮﺿﺔ ﻟﻠﺘﻔﻜ ﻚ ﻣﻘﺎرﻧـﺔ ﺑﻨﻈ اﺗﻬـﺎ ﻣﻦ ا ﺬﻧﺒﺎت ﻗﺼ ة اﻟﺪورة ﻣﺜ ا ﺬﻧ ﻞ ﺐ 67P/ ﺗﺸـﻮرﻳﻮﻣﻮف - ﺟ اﺳـﻴﻤﻴﻨﻜ ﻮ اﻟـﺬي زارﺗـﻪ ﻣﻬﻤ ـﺔ روزﻳﺘ ـﺎ اﻟﺘﺎﺑﻌ ـﺔ ﻟﻮﻛﺎﻟــﺔ اﻟﻔﻀ ـﺎء اﻷوروﺑﻴ ـﺔ إﻻ أن ﺳـﺒﺐ ذﻟ ـﻚ ﻻ ﻳ ـﺰال ﻏ ـ ﻣﻌـﺮوف . ﺗﺸـ اﻟﺪراﺳـﺎت إﱃ أن ا ـﺬﻧ ﺒﺎت ﻃﻮﻳﻠﺔ اﻟﺪورة ﺗﻘ ﴤ ﻓـﱰات زﻣﻨﻴـﺔ ﻃﻮﻳﻠـﺔ اً ﺑﻌﻴﺪ ﻋﻦ اﻟﺸﻤﺲ ﻣﺎ ﻳﺠﻌـﻞ ﺗـﺮاﻛﻢ اﻟﺜﻠـﻮ ج واﻟﻐﺒﺎر ﻋﲆ أﺳﻄﺤﻬﺎ أﻛﺜـﺮ ﻛﺜﺎ ﻓـﺔ ﻛﻤـﺎ أن ﺗﻌﺮﺿﻬﺎ اﻟﻨﺎدر ﻟﻺﺷﻌﺎع اﻟﺸﻤﴘﻗﺪ ﻳﺆدي إﱃ ﺗﻜﻮﻳﻦ ﻃﺒﻘﺎت ﻣﺘﻤﺎﺳﻜﺔ ﻣﻦ اﻟﻐﺒـﺎر ﺗﻌﻴـﻖ ﺗﺒﺨﺮ ا ﻮاد اﻟﺪاﺧﻠﻴﺔ ﺑﺸﻜﻞ ﻣﺘﻮازن . ﻋﻨﺪ اﻻﻗﱰاب ا ﻔﺎﺟﺊ ﻣﻦ اﻟﺸﻤﺲ ﻳﻤﻜـﻦ أن ﻳﺆدي اﻟﺘﺴﺨ ﻏ ا ﺘﻜﺎﻓﺊ إﱃ ﺗﻮﻟﻴﺪ ﺿﻐﻂ داﺧﲇ ﻋﺎﱄ، ﻣﻤﺎ ﻳﺘﺴﺒﺐ ﰲ اﻧﻔﺠﺎر أﺟﺰاء ﻣﻦ اﻟﻨﻮاة أو ﺗﻔﻜﻜﻬﺎ إﱃ ﺷﻈﺎﻳﺎ . ﻫﺬه اﻟﻌﻤﻠﻴـﺎت ﺗﺠﻌﻞ دراﺳﺔ ﻫـﺬه ا ـﺬﻧّﺒﺎت ﻓﺮﺻـﺔ ﻧـﺎدرة ﻟﻔﻬﻢ ﺗﻄﻮر ﺑﻨﻴﺘﻬﺎ اﻟﺪاﺧﻠﻴـ ﺔ وا ـﻮاد اﻷوﻟﻴـﺔ ﻟﻠﻨﻈﺎم اﻟﺸﻤﴘ وﻣﻦ ا ﻘـﺮر إﻃـﻼق ﻣﻬﻤـﺔ ﻛﻮﻣﻴـﺖ إﻧﱰﺳـﻴﺒﺘﻮر ﰲ ﻧﻬﺎﻳـﺔ ﻫــﺬ ا اﻟﻌﻘـﺪ ﻟﺘﻜﻮن أول ﻣﻬﻤﺔ ﺗﺰور ﻣﺬﻧّﺒ ﺎً ﻃﻮﻳﻞ اﻟـﺪورة . ﻗﺎل ا ﺆﻟﻒ ا ﺸﺎرك ﻛﻮﻟ ﺳـﻨﻮدﻏﺮاس ﻣـﻦ ﺟﺎﻣ ﻌـﺔ إدﻧــﱪة ﰲ اﺳـﻜﺘﻠﻨﺪا :» ﺳﺘﺴـﺎﻋﺪﻧﺎ ارﺻﺎد ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﻌﺮﺿﻴﺔ ﻟﻬﺬا ا ـﺬﻧّ ﺐ ﻋﲆ ﻓﻬﻢ أﺳﺒﺎب ﺗﻔﻜﻚ ﺑﻌﺾ ا ﺬﻧ ﺒﺎت ﻃﻮﻳﻠﺔ اﻟﺪورة ﻛﻤﺎ ﺗﻤﻨﺤﻨﺎ أول ﻧﻈﺮة ﺗﻔﺼﻴﻠﻴﺔ ﻋـﲆ ﺑﻨﻴﺘﻬﺎ اﻟﺪاﺧﻠﻴﺔ « . »: وأﺿﺎف ﺳـﺘُﻜﻤﻞ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ اﻟﺠﺪﻳـﺪة اﻟﺮؤﻳﺔ اﻟﺘﻔﺼﻴﻠﻴﺔ اﻟﺘﻲ ﺳﻨﺤﺼﻞ ﻋﻠﻴﻬـﺎ ﻣـﻦ ﻣﻬﻤﺔ ﻛﻮﻣﻴﺖ إﻧﱰ ﺳﻴﺒﺘﻮر ﻛﻤـﺎ ﺳﺘﺴـﺎﻋﺪ ﰲ اﺧﺘﻴﺎر اﻟﻬﺪف ا ﻨﺎﺳﺐ ﻟﻠﻤﻬﻤﺔ «. ﺴــﺘﻌﺮض ــﺪﻳﻮ اﻟﻤﺘﺤــﺮك ﺛــﻼثﺻـﻮراﻟﺘﻘﻄﻬـﺎ ﺗﻠﺴــ ﻮبﻫﺎﺑـﻞ اﻟﻔﻀـﺎﺋﻲ ﻫـﺬا اﻟﻔ اﻟﺘــﺎﺑﻊ ﻟﻮ ﺎﻟــﺔ ﻧﺎﺳـﺎ وو ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ ﻟﻠﻤﺬﻧﺐ اﻟﻤﺘﻔﺘﺖ C/2025 K1 (ATLAS) أو K1 اﺧﺘﺼﺎر اً اﻟﺘﻘﻄﺖ واﻟ ﻣﻦ 8 إﻟــﻰ 10 ﻧــﻮﻓﻤ 2025 . ــﺎف اﻟﺘﺼــﻮﻳﺮ اﻟﻔﻀــﺎﺋﻲ اﻟﺘــﺎﺑﻊ ﻟﺘﻠﺴــ ﻮب اﻟﺘﻘﻄﻬــﺎ ﻣﻄ ﺗﻈﻬــﺮﻫــﺬﻩ اﻟﺼــﻮراﻟــ ﻫﺎﺑﻞ اﻟﺘﻔ ﻚ اﻟﺘﺪر ﺠﻲ ﻟﻠﻤﺬﻧﺐ ﻋﻠﻰﻣﺪارﺛﻼﺛﺔ أ ﺎم . رﺻﺪ ﺗﻠﺴ ﻮب ﻫﺎﺑﻞ ﺗﻔﺘﺖ اﻟﻤـﺬﻧﺐ K1 إﻟـﻰ أرﻌـﺔ أﺟﺰاء ﻋﻠﻰ اﻷ ﻗﻞ ﻟ ﻞ ﻣﻨﻬﺎ ﻏـﻼف ﻣﻤـ ـ وﻫـﻮ ﻋ ـﺎرﺗ ﺎرة ﻋـﻦﺳـﺤﺎ ﺔ ﻣـﻦ اﻟﻐـﺎز واﻟﻐ ﺤـ ﻂ ﻨـﻮاة اﻟﻤـﺬﻧﺐ ـاﻟ . ﺠﻠ ﺪ ﺔ ﺗﻤﻜﻦ ﺗﻠﺴ ﻮب ﻫﺎﺑﻞ ﻣﻦ ﺗﻤﻴ اﻷﺟﺰاء ﺑﻮﺿﻮح ﻟﻜﻨﻬﺎ ﺪت ﻣﻦ اﻷرضﻓﻲ ذﻟـﻚ اﻟﻮ ﻗـﺖ ﻛ ﻘـﻊ ﺎﻟ ﺎد ﻤﻜﻦ ﺗﻤﻴ ﻫﺎ ﻖوﺛ . ﺗﻠﺴ ﻮب ﻫﺎﺑﻞ ﺗﺴﻠﺴﻞ اﻷﺣﺪاث وأوﺿﺢ ﺪﻗﺔ ﻛ ﻒﺣﺪث اﻟﺘﻔﺘﺖ . [NASA, ESA, D. Bodewits (Auburn), J. DePasqu le (STScI)] - ﻣﺎﻳﻮ ﻳﻮﻧﻴﻮ 2 0 2 6