Free Astronomy Magazine September-October 2025 ARABIC VERSION

connection to other star systems. They carry information about the chemicalelementsthatwerepresent when and where they formed, which gives scientists insight into howplanetarysystemsformatdis- tant stars throughout our galaxy’s history — including stars that have since died out. 3I/ATLAS, formally designated Com- et C/2025 N1 (ATLAS), is only the third interstellar object ever discov- ered after 1I/ ‘ Oumuamua in 2017 andthecomet2I/Borisovin2019. While astronomers think many inter- stellar objects exist, and likely pass through our Solar System on a regu- larbasis,theyareexceptionallydif- ficult to capture since they are only visiblewhenthey’recloseenough to see and when our telescopes are pointing in the right place at the right time. Multiple teams of astronomers around the globe are using a wide variety of telescopes to observe 3I/ATLASduringitstemporaryvisit toourSolarSystem,allowingthem to collectively determine some of thecomet’skeycharacteristics.Al- thoughmuchremainsunknown,itis alreadyclearthat3I/ATLASisunique compared to the two other known interstellar objects. Observations so farsuggestthat3I/ATLAShasanap- proximatediameterofatmost20 kilometers (12 miles), compared to ‘Oumua- mua’s diameter of 200 meters and Borisov’s of less than one kilometer. 3I/ATLAS’s larger size makesitabettertarget The comet also has an exceptionally eccentric orbit, where eccentricity describes how much an object’s or- bital pathway is ‘stretched out.’ An eccentricityof0isaperfectlycircular orbit, while an eccentricity of 0.999 is a very stretched-out ellipse. Anobjectwithaneccentricityabove 1 is on a path that does not loop back around the Sun, implying it comes from — and will return to — interstellar space. 3I/ATLAS has an eccentricity of 6.2, which is highly hyperbolic and ensures its classifica- tionasaninterstellarobject.Incom- parison,‘Oumuamuahadaneccen- tricity of about 1.2, and Borisov about 3.6. Right now, 3I/ATLAS is within Jupiter’sorbitatadistanceofabout 465 million kilometers (290 million miles) from Earth and 600 million kilometers(370millionmiles)from the Sun. The closest 3I/ATLAS will cometoEarthisapproximately270 millionkilometers(170millionmiles) on19December,thoughitwillpose nothreattotheplanet.Itwillreach its closest approach to the Sun around 30 October at a distance of 210 million kilometers (130 million miles) — just inside the orbit of Mars.Duringthiscloseapproach,it willbetravelingalmost25,000kilo- meters (15,500 miles) per hour. Although 3I/ATLAS is only the third interstellar object ever discovered, the astronomical community ex- pects many more to soon come into focus once NSF–DOE Vera C. Rubin Observatory, jointly funded by NSF and the U.S. Department of En- ergy’s Office of Science, begins its decade-long Legacy Survey of Space and Time (LSST). By repeatedly scanning the entire southernhemisphereskyeveryfew nights, Rubin will capture millions of objects moving throughout our Solar System, including an unpre- dictablenumberofnever-before- forscientiststostudy. seeninterstellarobjects.    SEPTEMBER-OCTOBER2025 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 13 ﺗﻈﻬــــــﺮ ﻫــــــﺬﻩ اﻟﺼـــــــﻮرة اﻟـــــــ ـــــــــــــ ــــــــــــﺎفﺟ ﻤ اﻟﺘﻘﻄﻬــــــــــــﺎ ﻣﻄ ﻣﺘﻌـــــــﺪد اﻷﺟـــــــﺮام ) GMOS-N ( ــ اﻟﺘــﺎﺑﻊ ﻟﺘﻠﺴــ ﻮبﺟ ﻤ ﻧــﻮر اﻟﻤـــﺬﻧﺐ /3I أﻃﻠـــﺲ وﻫـــﻮ ﺸـــﻖ ــﻒ ﻃﺮ ﻘـﮫ ﻋـ ﺣﻘـﻞ ﻧ ﻤـﻲﻛﺜ . ﺗﻠــــــــــﺘﻘﻂ اﻟﺼــــــــــﻮرة اﻟ ﻤــــــــــ أﺛــــــــــﺮ اﻟﻤـــــــﺬﻧﺐ اﻟﻤﻠـــــــﻮن أﺛﻨـــــــﺎء ﺗﺤﺮﻛـــــــﮫ ﻋــ اﻟﻨﻈـــﺎم اﻟﺸﻤﺴـــﻲ . ﺗﺄﻟﻔـــﺖ اﻟﺼــﻮرة ﻣــﻦ ﺗﻌﺮﻀــﺎت ﻣـﺄﺧﻮذة ﻣـﻦ ﺧـﻼل ﺛﻼﺛـﺔ ﻣﺮﺷـﺤﺎت ﺗﻈﻬــﺮ ـــــﺎﻷﻟﻮان اﻷ ﻤـــــﺮواﻷﺧﻀـــــﺮ ﻫﻨــــﺎ . واﻷزرق ـ ﻜــ اﻟــ ﺠﺰء اﻷ ﺴــﺮ ﻣــﻦ ــــــــﺔ اﻟﺼــــــــﻮرة ﻟ ﻜﺸــــــــﻒﻋــــــــﻦ ذؤا اﻟﻤــــــــــــــﺬﻧﺐ اﻟﻤ ﻌﻘــــــــــــــﺪة وﻫـــــــــــــــﻲ ـﺎرﺗﺤـ ﻂ ﺳﺤﺎ ﺔ ﻣﻦ اﻟﻐﺎز واﻟﻐ ﻨﻮاﺗﮫ اﻟ ـ . ﺠﻠ ﺪ ﺔ [International Gemini Observatory/NOIRLab/NS F/AURA/K.Meech(IfA/U. Hawaii)−ImageProcess- ing: Jen Miller & Mahdi Zamani (NSF NOIRLab)] ﻳُﻌﺪ ا ﺬﻧﺐ 3I / أﻃﻠﺲ ا ُﺴﻤﻰ رﺳﻤﻴ ﺎ ا ﺬﻧﺐ C/2025 N1) اﻃﻠ ـﺲ ( ﺛﺎﻟ ـﺚ ﺟﺴـﻢ ﺑـ ﻧﺠﻤﻲ ﻳ ﻜﺘﺸـﻒ ﻋـﲆ اﻹﻃـﻼق ﺑﻌـﺪ ا ـﺬﻧﺐ 1I/ أوﻣﻮاﻣــﻮا ﰲ ﻋــﺎم 2017 وا ــﺬﻧﺐ 2I/ ﺑﻮرﻳﺴﻮف ﰲ ﻋﺎم 2019 . ﰲ ﺣ ﻳﻌﺘﻘﺪ ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ أن اﻟﻌﺪﻳـ ﺪ ﻣـﻦ اﻷﺟﺮام ﺑ اﻟﻨﺠﻤﻴﺔ ﻣﻮﺟﻮدة وﻣـﻦ ا ـﺮﺟﺢ ﻬأﻧ ﺎ ﺗﻤﺮ ﻋﱪ ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ ﺑﺎﻧﺘﻈﺎم إﻻ أن رﺻﺪﻫﺎ ﺻﻌﺐ ﻟﻠﻐﺎﻳﺔ ﻧﻈﺮ اً ﻟﺼﻌﻮﺑﺔ رؤﻳﺘﻬـﺎ ﻓﻘﻂ ﻋﻨ ﺪﻣﺎ ﺗﻜﻮن ﻗﺮﻳﺒﺔ ﺑﻤﺎ ﻳﻜﻔﻲ ﻟﺮؤﻳﺘﻬـﺎ ﺎ ﺗ وﻋﻨﺪﻣ ﻮﺟﻪ ﺗﻠﺴﻜﻮﺑﺎﺗﻨﺎ إﱃ ا ﻜﺎن اﻟﺼﺤﻴﺢ اﻟﻮﻗﺖ ﰲ اﻟﺼـﺤﻴﺢ . ﺗﺴـﺘﺨﺪم ﻓـﺮق ﻓﻠﻜﻴـﺔ ﻣﺘﻌﺪدة ﺣﻮل اﻟﻌﺎﻟﻢ ﻣﺠﻤﻮﻋﺔ ﻣﺘﺒﺎﻳﻨـﺔ ﻣـﻦ اﻟﺘﻠﺴﻜﻮﺑﺎت ﻟﺮﺻﺪ ا ﺬﻧﺐ 3I/ أﻃﻠﺲ ﺧـﻼل زﻳﺎرﺗﻪ ا ﺆﻗﺘﺔ ﻟﻨﻈﺎﻣﻨﺎ اﻟ ﺸﻤﴘ ﻣﻤـﺎ ﻳﺘـﻴﺢ ﺧﺼﺎﺋﺼﻪ اﻟﺮﺋﻴﺴﻴﺔ ﺑﺸـﻜﻞ ﺟﻤـﺎﻋﻲ . ﻋـﲆ اﻟﺮ ﻏﻢ ﻣﻦ أن اﻟﻜﺜ ﻻ ﻳﺰال ﻣﺠﻬـﻮﻻً إﻻ أﻧـﻪ ﻣﻦ اﻟﻮاﺿﺢ ﺑﺎﻟﻔﻌـﻞ أن ا ـ ﺬﻧﺐ 3I / أﻃﻠـﺲ ﻓﺮﻳﺪ ﻣـﻦ ﻧﻮﻋـﻪ ﻣﻘﺎرﻧـﺔ ﺑـﺎﻟﺠﺮﻣ اﻟﺒـ ﻧ ﺠﻤﻴ ا ﻌﺮوﻓ اﻵﺧﺮﻳﻦ . ﺗﺸـ اﻷرﺻـﺎد ﺣﺘـﻰ اﻵن إﱃ أن ﻗﻄــﺮ ا ـ ﺬﻧﺐ 3I / أﻃﻠــﺲ ﻳﻘﺎرب 20 ) اً ﻛﻴﻠﻮﻣﱰ 12 ( ﻣﻴﻼً ﻣﻘﺎرﻧﺔ ﺑﻘﻄﺮ ا " ﺬﻧﺐ أوﻣﻮاﻣﻮا " اﻟﺒـﺎﻟﻎ 200 ﻣـﱰ وﻗﻄـﺮ ا " ﺬﻧﺐ ﺑﻮرﻳﺴﻮف اﻟﺬي" ﻳﻘﻞ ﻋـﻦ ﻛﻴﻠـﻮﻣﱰ . واﺣﺪ ﻳﺠﻌﻞ ﺣﺠﻢ ا ﺬﻧﺐ 3I / أﻃﻠﺲ اﻷﻛـﱪ ﺎً ﻣﻨﻪ ﻫﺪﻓ أﻓﻀﻞ ﻟﻠﻌﻠﻤﺎء ﻟﺪ راﺳـﺘﻪ . ﻟﻠﻤـﺬﻧﺐ أﻳﻀ ﺎ ﻣﺪار ﺷﺪﻳﺪ اﻻﺳﺘﻄﺎﻟﺔ ﺑﺸﻜﻞ اﺳﺘﺜﻨﺎﺋﻲ اﻻﺳﺘﻄﺎﻟﺔ ﺼﻒ ﺗ ﺣﻴﺚ " ﺗﻤﺪد " ﻣﺪى ا ﺴـﺎر ا ﺪاري ﻟﻠﺠ . ﺮم ﻋﻨﺪﻣﺎ ﺗﻜﻮن اﻻﺳﺘﻄﺎﻟﺔ ﺻﻔﺮاً ﻳﻜـﻮن ا ـﺪار ﺎً داﺋﺮﻳـ ﺎً ﺗﻤﺎﻣـ اﻣـﺎ اذا ﺑﻠﻐـﺖ اﻻس ٠.٩٩٩ ﻫﻮ ﻗﻄﻊ ﻧﺎﻗﺺ ﻣﻤﺘﺪ ﻟﻠﻐﺎﻳﺔ . ﻳﺄﺗﻲ ﻣﻦ اﻟﻔﻀﺎء اﻟﺒ ﻧ ﺠﻤﻲ وﺳﻴﻌﻮد إﻟﻴـﻪ . ﻠﻚ ﻳﻤﺘ ا ﺬﻧﺐ 3I / أﻃﻠﺲ اﺳـﺘﻄﺎﻟﺔ ﻣﺪارﻳـﺔ ﺑﻘﻴﻤﺔ 6.2 وﻫﻲ ﻗﻴﻤﺔ ﻋﺎﻟﻴﺔ ﺟـﺪاً وﻳﻀـﻤﻦ ﺗﺼ ﻨﻴﻔﻪ ﻛﺠﺴﻢ ﺑ ﻧﺠﻤﻲ و ﺑﺎ ﻘﺎرﻧﺔ ﺒﻠـﻎ ﺗ اﺳــﺘﻄﺎﻟﺔ ﻣــﺪار " أوﻣﻮاﻣــﻮ " ا ﺣــﻮاﱄ 1.2 وﺑﻮرﻳﺴﻮف ﺣﻮاﱄ 3.6 . ﻳﻘﻊ ا ﺬﻧﺐ 3I / أﻃﻠﺲ ﺎً ﺣﺎﻟﻴ ﺿﻤﻦ ﻣﺴـﺎﻓﺔ ﻛﻮﻛــﺐ ا ﺸــﱰي أي ﺣــﻮاﱄ 465 ﻣﻠﻴــﻮن ) ﻛﻴﻠﻮﻣﱰ 290 ﻣﻠﻴﻮن ﻣﻴﻞ ﻣ( ﻦ اﻷرض و 600 ﻣﻠﻴـﻮن ﻛﻴﻠـﻮﻣﱰ ) 370 ﻣﻠﻴـﻮن ﻣﻴـﻞ ﻣـﻦ ( اﻟﺸ ـﻤﺲ . ﺳﻴﺼـﻞ ا ـﺬﻧﺐ 3I / أﻃﻠ ـﺲ إﱃ اﻷرضﻋــﲆ ﻣﺴ ـﺎﻓﺔ ﺗﻘ ـﺎرب 270 ﻣﻠﻴ ـﻮن ) ﻛﻴﻠﻮﻣﱰ 170 ﻣﻠﻴﻮن ﻣﻴـﻞ ﰲ ( 19 دﻳﺴـﻤﱪ ﻣﻊ أﻧﻪ ﻟﻦ ﻳﺸـﻜﻞ أي ﺧﻄـﺮ ﻋـﲆ اﻟﻜﻮﻛـﺐ . ﺳﻴﺼﻞ إﱃ أﻗﺮب ﻧﻘﻄﺔ ﻟﻪ ﻣﻦ اﻟﺸﻤﺲ ﺣﻮاﱄ 30 أﻛﺘﻮﺑﺮ ﻋﲆ ﻣﺴﺎﻓﺔ 210 ﻣﻼﻳ ﻛﻴﻠـﻮﻣﱰ ) 130 ﻣﻠﻴـﻮن ﻣﻴـﻞ (- داﺧـﻞ ﻣـﺪار ا ـﺮﻳﺦ ﺎﴍةً ﻣﺒ . ﺧـﻼل ﻫـﺬا اﻻﻗـﱰاب اﻟﻘﺮﻳـﺐ ﻟـﻪ ﺳﻴﺴﺎﻓﺮ ﺑﴪﻋﺔ ﺗﻘـﺎرب 25 أﻟـﻒ ﻛﻴﻠـﻮﻣﱰ ) 15,500 ( ﻣﻴﻞ . ﰲ اﻟﺴﺎﻋﺔ ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ أن ا ﺬﻧﺐ 3I / أﻃﻠﺲ ﻫﻮ ﺛﺎﻟﺚ ﺟﺴﻢ ﺑ ﻧﺠﻤﻲ ﻳُﻜﺘﺸﻒ ﻋﲆ اﻹﻃﻼق ﻳﺘﻮﻗﻊ ا ﺠﺘﻤﻊ اﻟﻔﻠﻜﻲ اﻛﺘﺸﺎف ا ﺰﻳﺪ ﻗﺮﻳﺒ ﺑﻤ ﺎً ﺠﺮد أن ﻳﺒ ﺪأ ﻣﺮﺻﺪ ﻓ ا ﳼ روﺑ . اﻟﺘﺎﺑﻊ ﺆﺳﺴﺔ اﻟﻌﻠﻮم ا ﻟﻮﻃﻨﻴـﺔ ووزارة اﻟﻄﺎﻗـﺔ اﻷﻣﺮﻳﻜﻴـﺔ وا ﻤﻮل ﺑﺸﻜﻞ ﻣﺸﱰك ﻣﻦ ﻣﺆﺳﺴﺔ اﻟﻌﻠـﻮم اﻟﻮﻃﻨﻴﺔ وﻣﻜﺘﺐ اﻟﻌﻠﻮم اﻟﺘﺎﺑﻊ ﻟﻮزارة اﻟﻄﺎﻗﺔ اﻷﻣﺮﻳﻜﻴﺔ ﻣﺴﺤﻪ اﻟﺸﺎﻣﻞ ﻟﻠﻔﻀﺎء واﻟﺰﻣـﺎن اﻟﺬي ﻳﺴﺘﻤﺮ ﻟﻌﻘﺪ ﻣﻦ اﻟﺰﻣﻦ . ﻣﻦ ﺧﻼل ا ﺴـﺢ اﻟﺸـﺎﻣﻞ وا ﺘﻜـﺮر ﻟﺴـﻤﺎء ﻧﺼﻒ اﻟﻜ ﺮة اﻟﺠﻨﻮﺑﻲ ﺑﺄﻛﻤﻠﻬﺎ ﻛﻞ ﺑﻀﻊ ﻟﻴﺎلٍ ﺳـﻴﻠﺘﻘﻂ ﻣﺮﺻـﺪ روﺑـ ﻣﻼﻳ ـ اﻷﺟـﺮام ا ﺘﺤﺮ ﻛﺔ ﰲ ﺟﻤﻴﻊ أﻧﺤﺎء ﻧﻈﺎﻣﻨﺎ اﻟﺸﻤـ .ﴘـ ﻳﺘﻀﻤﻦ ذﻟﻚ ﻋﺪد اً ﻏ ﻣﺘﻮﻗﻊ ﻣـﻦ اﻷﺟﺴـﺎم ﺑ اﻟﻨﺠﻤﻴﺔ اﻟ ﺘﻲ ﻟﻢ ﺗُﺮﺻـﺪ ﻣـﻦ ﻗﺒـﻞ ﻣﻤـﺎ ﻳﻔﺘﺢ آﻓﺎﻗًﺎ ﺟﺪﻳﺪة ﻟﻔﻬﻤﻨﺎ ﻟﻠﻜﻮن . ﺳﺘُﺤﺪث ﻫﺬه اﻟ ﺒﻴﺎﻧﺎت ﺛﻮرة ﺣﻘﻴﻘﻴﺔ ﰲ ﻋﻠـﻢ اﻟﻔﻠ ﻚ ﻛﺎﺷﻔﺔً ﻋﻦ أﴎار ﻟـﻢ ﻧﻜـﻦ ﻟﻨﺘﺨﻴﻠﻬـﺎ . ﻗﻂ ﺳﺘﻘﺪم ﻟﻨﺎ ﺤﺔ ﻓﺮﻳﺪة ﻋﻦ اﻟﺪﻳﻨﺎﻣﻴﻜﻴﺎت اﻟﺨﻔﻴﺔ ﻟﻨﻈﺎﻣﻨﺎ اﻟﺸﻤﴘ وﻣﺎ ﺑﻌﺪه ﻣﻤﺎ ﻳﻐ ﻓﻬﻤﻨﺎ ﻟﻠﻤﺠﺮات واﻟﻜﻮاﻛﺐ اﻟﺒﻌﻴﺪة و ﺳﻨﺘﻤﻜﻦ ﻣﻦ اﻛﺘﺸﺎف ﻇﻮاﻫﺮ ﻓﻠﻜﻴﺔ ﺟﺪﻳﺪة، وﺗﺤﺪﻳـﺪ ﻣﺴﺎرات أﺟﺴﺎم ﻓﻀﺎﺋﻴﺔ ﻏ ﻣﻌﺮوﻓﺔ . اﻻﺳﺘﻄﺎﻟﺔ 0.999 ﻓـﺎن ا ـﺪار ﻳﺼـﺒﺢ ﺎً ﻗﻄﻌـ ﻧﺎﻗﺼـ ﺎً ﺷـﺪﻳﺪ اﻻﺳ ـﺘﻄﺎﻟﺔ . إن اﻟﺠ ـﺮم اﻟ ـﺬي ﺗﻜﻮن اﺳﺘﻄﺎﻟﺔ ﻣﺪاره أﻋﲆ ﻣﻦ 1 ﻳﻜـﻮن ﻋـﲆ ﻣﺴـﺎر ﻻ ﻳـﺪور ﺣﻮل اﻟﺸﻤﺲ ﻣﻤـﺎ ﻳﻌ ﻨـﻲ أﻧـﻪ اﺗﻲ ﺳﺒﺘﻤﺒﺮ - ﺃﻛﺘﻮﺑﺮ 2 0 2 5