Free Astronomy Magazine March-April 2026 ARABIC VERSION

A E ficiallightfromametropolitanregion xtensiveurbanskyglowshowshowarti- createsabrightdomeabovethehorizon, significantlyreducingnight-skydarkness over large areas. [A. Anfuso] 500-900 nm range; it was thus ex- tremelyeffectiveatmonitoringthe traditionalyellow-orangepartofthe spectrum emitted by high-pressure sodium (HPS) lamps, which domi- nated outdoor lighting worldwide. Unfortunately, the emission spec- trum of white LEDs is particularly strong in the blue region, peaking at around 450-460 nm, meaning it falls almost entirely out- side the VIIRS detection range. In a 2014 studyby C. Cao & B. Bai, it is estimated that approxi- mately 34% of the radi- ant power of typical white LED lighting falls outsideVIIRS’sresponse, and as the use of LED technology ramps up worldwide, this number is likely set to rise. Fortunately, this gap is now being filled with fresh data coming from the SDGSAT-1 (Sustain- able Development Sci- enceSatellite1),thefirst satellitespecificallydesignedforthe UN’s 2030 Agenda for Sustainable Development.LaunchedbytheChi- nese Academy of Sciences in 2021, it provides Earth observation data with thermal infrared, low-light, and multispectral sensors to moni- tor human-nature interactions, ur- bandevelopment,andenvironmen- tal changes. ComparativestudiesbetweenVIIRS and SDGSAT-1 show a significant and systematic underestimation of global light pollution, particularly around urban centres. Where VIIRS data suggested stable or even de- cliningtrends,SDGSAT-1revealeda rapidincreaseinblue-richemissions, signalling a significant miscalcula- tion in our previous estimations. denseurbanskyline withartificiallight- ingsignificantlyincreasess kybrightnessandpre- vents the visibility of stars. [A. Anfuso] اﻟﺘﻮﻫﺞ اﻟﺴﻤﺎوي اﻟـﺤﻀﺮي اﻟﻮاﺳﻊ ﻳﻮﺿﺢ ﻛ ﻒ أن اﻟﻀﻮء ــﺔ اﻻﺻــﻄﻨﺎﻋﻲ اﻟﺼــﺎدر ﻣــﻦ ﻣﻨﻄﻘــﺔ ﺣﻀـﺮ ﺔ ﻛــ ى ﻨﺸــﻰء ﻗ ﻣﻀــﻴﺌﺔ ﻓــﻮق اﻷﻓــﻖ ﻣﻤــﺎ ﻘﻠــﻞ ﺸــ ﻞ ﻛﺒــ ﻣــﻦ ﻇﻠﻤــﺔ ﺳــﻤﺎء اﻟﻠﻴﻞ ﻋﻠﻰﻣﺴﺎﺣﺎت واﺳﻌﺔ [A. Anfuso] اﻟﱪﺗﻘﺎﱄ اﻟﺘﻘﻠﻴﺪي ﻣﻦ اﻟﻄﻴﻒ اﻟﺼﺎدر ﻋـﻦ ﻣﺼﺎﺑﻴﺢ اﻟﺼﻮدﻳﻮم ﻋﺎﻟﻴﺔ اﻟﻀﻐﻂ )HPS ( اﻟﺘﻲ ﻫﻴﻤﻨﺖ ﻋ ﲆ اﻹﺿﺎءة اﻟﺨﺎرﺟﻴﺔ ﻋﺎ ﻴـﺎً ﻟﻜﻦ ﻃﻴﻒ اﻧﺒﻌﺎث ﻣﺼﺎﺑﻴﺢ LED اﻟﺒﻴﻀﺎء ﻗﻮي ﻋﲆ ﻧﺤﻮ ﺧﺎص ﰲ ا ﻨﻄﻘـﺔ اﻟﺰرﻗـﺎء ﺑﺬروة ﺗﻘﺎرب 450 –460 ﺎﻧﻮﻣﱰ ﻧ ﻣﺎ ﻳﻌﻨـﻲ أن ﺟﺰءاً ﻛﺒ اً ﻣﻨﻪ ﻳﻘﻊ ﺧﺎرج ﻧﻄﺎق ﻛﺸﻒ ﺟﻬﺎز . ﻓ س ﰲ دراﺳﺔ ﻋﺎم 2014 أﺟﺮاﻫﺎ اﻟﺒﺎﺣﺜﺎن ﺗﺸﺎﻧﻐﻴﻮﻧﻊ ﻛﺎو و ﻳﺎن ﺑﺎي ﻗُـﺪّر أن ﻧﺤﻮ 34 % اﻟﻨﻘﺺﺣﺎﻟﻴﺎً أ ﻧﺤــﻮ 34 % ﻣــﻦ اﻟﻘــﺪرة اﻹﺷــﻌﺎﻋﻴﺔ ﺼــﺎﺑﻴﺢ LED اﻟﺒﻴﻀــﺎء اﻟﻨﻤﻮذﺟﻴــﺔ ﻳﻘــﻊ ﺧﺎرج اﺳﺘﺠﺎﺑﺔ ﺟﻬﺎز ﻓـ س وﻣــﻊ اﻟﺘﻮﺳــﻊ اﻟﻌــﺎ ﻲ ﰲ اﺳ ــﺘﺨﺪام ﻣﺼ ــﺎﺑﻴﺢ LED ﻳﺘﻮﻗﻊ أن ﺗﺮﺗﻔﻊ ﻫﺬه اﻟﻨﺴـﺒﺔ وﻟﺤﺴـ ﻦ اﻟﺤ ـﻆ ﻳﺴ ـﺪ ﻫ ـﺬا اﻟﻨﻘﺺ ﺣﺎﻟﻴﺎً ﺑﺒﻴﺎﻧﺎت ﺟﺪﻳـﺪة ﻣـــﻦ اﻟﻘﻤـــﺮ اﻟﺼـــﻨﺎﻋﻲ SDGSAT-1 وﻫـﻮ أول ﻗﻤ ـ ﺮ ﻤﺻ ﻢ ﺧﺼﻴﺼﺎً ﻟـﺪﻋﻢ أﺟﻨـﺪة اﻷﻣﻢ ا ﺘﺤـﺪة 2030 ﻟﻠﺘﻨﻤﻴـﺔ ا ﺴـﺘﺪاﻣﺔ . أُﻃﻠـﻖ ﻣـﻦ ﻗﺒـﻞ اﻷ ﻛﺎدﻳﻤﻴـﺔ اﻟﺼـﻴﻨﻴﺔ ﻟﻠﻌﻠـﻮم ﻟﻠﻌﻠ ـﻮم ﻋ ـﺎم 2021 وﻳــﻮﻓﺮ ﺑﻴﺎﻧﺎت رﺻﺪ أرﴈ ﺑﺎﺳﺘﺨﺪام ﻋـﺎم 2021 وﻳــﻮﻓﺮ ﺑﻴﺎﻧـﺎت رﺻـﺪ أرﴈ ﺑﺎﺳـﺘﺨﺪام ﻣﺴﺘﺸــﻌ ﺮات اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤــﺮاء اﻟﺤﺮارﻳ ـﺔ واﻹﺿـﺎءة اﻟﺨﺎﻓﺘــﺔ وﻣﺘﻌﺪدة اﻷﻃﻴﺎف ﺮاﻗﺒﺔ اﻟﺘﻔـﺎﻋﻼت ﺑـ اﻹ ﻧﺴــﺎن واﻟﻄﺒﻴﻌ ـﺔ إﺿـﺎﻓﺔ إﱃ اﻟﺘﻄــﻮر اﻟﺤ ـ ﴬي ـ واﻟﺘﻐــ ات اﻟﺒﻴﺌﻴ ـﺔ ﺗ. ﻈﻬــﺮ اﻟﺪراﺳﺎت ا ﻘﺎرﻧﺔ ﺑ ﺟﻬﺎز اﻟﻘﻤﺮ و ﻓ س اﻟﺼــﻨﺎﻋﻲ SDGSAT-1 وﺟــﻮد ﺗﻘﻠﻴــﻞ ﺗﻘـﺪﻳﺮي ﻣﻨﻬﺠـﻲ وﻛﺒـ ا ﺣـﻮل ﻟﺘﻠـﻮث ﻲ ـــــ ــــ اﻟﻀﻮﺋﻲ اﻟﻌﺎ ﻲ ﺣﻮل اﻟﻨﻄﺎﻗﺎت اﻟﻌﻤﺮاﻧﻴـﺔ ﻓﻔﻲ ﺣ أﺷﺎرت ﺑﻴﺎﻧﺎت ﺟﻬﺎز إﱃ ﻓـ س اﺳـﺘﻘﺮار أو ﺣﺘـﻰ اﻧﺨﻔـﺎض اﻻﺗﺠﺎﻫـﺎت ﻛﺸﻒ اﻟﻘﻤﺮ اﻟﺼـﻨﺎﻋﻲ SDGSAT-1 ﻋـﻦ زﻳﺎدة ﴎﻳﻌﺔ ﰲ اﻻﻧﺒﻌﺎﺛﺎت اﻟﻐﻨﻴﺔ ﺑـﺎﻟﻠﻮن اﻷزرق ﻣﺎ ﻳﺪل ﻋﲆ وﺟﻮد ﺧﻄﺄ ﻣﻠﺤـﻮظ ﰲ ﺗﻘﺪﻳﺮاﺗﻨﺎ اﻟﺴﺎﺑﻘﺔ . ﻟﻘﺪ ﻛﺎن اﻟﻀﻮء اﻷزرق ا ﺤ ﺮك اﻟﺮﺋﻴﴘ ﻟﻠﺘﻠﻮث اﻟﻀـﻮﺋﻲ اﻟﺤـﺪﻳﺚ ﻏﺎﺋﺒﺎً إﱃ ﺣﺪ ﻛﺒ ﻋﻦ ﻣﺠﻤﻮﻋﺎت اﻟﺒﻴﺎﻧـﺎت ـ اﻷﻓﻖ اﻟﻌﻤﺮاﻧﻲ اﻟﻜﺜ ﻒ اﻟﻤﺼﺤﻮب ﺑﺈﺿﺎءة اﺻﻄﻨﺎﻋ ﺔ ﻳﺮﻓﻊﺳـﻄﻮع اﻟﺴـﻤﺎء ﺪرﺟـﺔ ﻛﺒـ ة وﻳﺤﺪ ﻣﻦ إﻣ ﺎﻧ ﺔ رﺻﺪ اﻟﻨﺠﻮم [A. Anfuso]