Free Astronomy Magazine March-April 2026 ARABIC VERSION

Blue light, the dominant driver of modern light pollution, was largely absent from the datasets that guide global assessment and policy discus- sions: the night sky changed faster than we could detect with our in- struments, and it’s now a significant problem. These new satellite data depict a clear and uncomfortable picture: totalartificialradianceisconstant-ly rising globally, even in regions where data suggest a decrease in energy consumption for lighting. The rapid rise in light pollution is driven by the increasing efficiency of LEDs in a paradox known as the “reboundeffect”:lighthasbecome cheap — so we use more of it. Also,asisoftenthecase,newinstal- lationsaresignificantlybrighterthan thelampstheyreplace,although stillcheaper,generatingsavingsthat are frequently reinvested to illumi- nate areas that were previously left dark,suchasparks,architecturalfa- cades, and suburban corridors. Theshifttowardblue-richlighting is particularly damaging to astron- omy,asshorterwavelengthsscatter far more efficiently than longer ones;itisestimatedthatbluelight around 440 nm scatters about 2.5 times more than the green-yellow light (550 nm). This means that a single white LED contributesdisproportionatelymore to the diffuse dome of skyglow, even if its total lumen output is lower than that of the lamp it re- placed.Andthephenomenonisnot limitedtourbancentres:scattered light can travel long distances, de- gradingtheskyfarbeyondthecity and reaching remote areas once considered safe. Thegrowingimpact of artificial skyglow has thereforenot gone unnoticed within the as- tronomical community as even ma- jorground-basedobservatories,such as the Vera C. Rubin on Cerro Pa- chón and the Very Large Telescope on Cerro Paranal, both in Chile, are nowaffectedbylightpollution,with severe consequences for their effi- ciency and scientific output. Large telescopes operate close to physical and technical limits, and wide-field imaging programmes and time- domain surveys rely on stable, dark skybackgroundsforthedetection of faint and diffuse signals. As sky brightness increases, the impact on scientificoutputisinevitable,partic- ularly for studies targeting low-sur- face-brightness phenomena. MARCH-APRIL2026 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 7 اﻟﺘﻲ ﺗﻮﺟﻪ اﻟ ﺘﻘﻴﻴﻤﺎت اﻟﻌﺎ ﻴﺔ واﻟﻨﻘﺎﺷـﺎت اﻟﺴﻴﺎﺳﻴﺔ : ﻟﻘﺪ ﺗ ﻐ ت ﺳـﻤﺎء اﻟﻠﻴـﻞ أﴎع ﻣﻤﺎ اﺳﺘﻄﺎﻋﺖ أدواﺗ ﻨﺎ رﺻﺪه وأﺻﺒﺢ اﻷﻣﺮ اﻵن ﻣﺸﻜﻠﺔ ﻛﺒ ة . ﺗﺮﺳﻢ ﻫﺬه اﻟﺒﻴﺎﻧـﺎت اﻟﻔﻀـﺎﺋﻴﺔ اﻟﺠﺪﻳـﺪة ﺻﻮرة واﺿـﺤﺔ وﻏـ ﻣﺮﻳﺤـﺔ : اﻹﺷـﻌﺎع اﻻﺻﻄﻨﺎﻋ ﻲ اﻟﻜﲇ ﰲ ازدﻳﺎد ﻣﺴﺘﻤﺮ ﻋﺎ ﻴـﺎً ﺣﺘﻰ ﰲ ا ﻨﺎﻃﻖ اﻟﺘﻲ ﺗﺸ اﻟﺒﻴﺎﻧـ ﺎت ﻓﻴﻬـﺎ إﱃ اﻧ ﺨﻔﺎض اﺳﺘﻬﻼك اﻟﻄﺎﻗـﺔ ﻟﻺﺿـﺎءة . وﻳ ﻌﺰى اﻻرﺗﻔﺎع اﻟﴪﻳﻊ ﰲ اﻟﺘﻠﻮث اﻟﻀﻮﺋﻲ إﱃ ﺗﺰاﻳﺪ ﻛﻔﺎءة LED ﺿﻤﻦ ﻣﻔﺎرﻗﺔ ﺗﻌﺮف " ﺑﺎﺳﻢ ﺗﺄﺛ اﻹ " رﺗﺪاد ﺣﻴﺚ أﺻﺒﺢ اﻟﻀـﻮء رﺧﻴﺼﺎً ﻟﺬا ﻧﺴﺘﺨﺪم ا ﺰﻳﺪ ﻣﻨﻪ وﻛﻤﺎ ﻳﺤﺪث ﻏﺎﻟﺒﺎً ﻓﺈن اﻟﱰﻛﻴﺒﺎت اﻟﺠﺪﻳﺪة ﺗﻜـﻮن أﻛﺜـﺮ ﺳﻄﻮﻋﺎً ﺑﻜﺜ ﻣـﻦ ا ﺼـﺎﺑﻴﺢ اﻟ ﺘـ ﻲ ﺗﺤـﻞ ﻣﺤﻠﻬﺎ ورﻏﻢ أﻧﻬﺎ أﻗﻞ ﻛﻠﻔﺔ ﻓﺈن اﻟﻮﻓﻮرات ا ﺘﺤﻘﻘﺔ ﻳ ﻌﺎد اﺳﺘﺜﻤﺎرﻫﺎ ﻛﺜـ اً ﰲ إﻧـﺎرة ﻣﻨــﺎﻃﻖ ﻛﺎﻧــﺖ ﺳــﺎﺑ ﻘﺎً ﻣﻈﻠﻤــﺔ ﻣﺜــﻞ ا ﺘﻨﺰﻫﺎت، واﻟﻮاﺟﻬﺎت ا ﻌﻤﺎرﻳﺔ، وا ﻤﺮات ﺗـــــﻮﻫﺞ اﻟﺴــــــﻤﺎء واﺳــــــﻊ اﻟﻨﻄــــــﺎق ﻧــــــﺎﺗﺞ ﻋــــــﻦ اﻹﺿﺎءة اﻻﺻﻄﻨﺎﻋ ﺔ واﻟﻤﺘﻀ ﻢ ﻔﻌﻞ ﻟﺘ ﻌـ ـاﻟ ﺠﻮيﻓﻮق ﻣﻨﻄﻘﺔ ﻋﻤﺮاﻧ ﺔ [A. Anfuso] ا ﺘﻨﺰﻫﺎت وا ﻟﻮاﺟﻬﺎت ا ﻌﻤﺎرﻳﺔ وا ﻤـﺮات اﻟﻀ ﻌﺪ اﻟ ﻳ. ﺔﺣﻴ ﺎ ﺘﺤﻮل ﻧﺤﻮ إﺿـﺎءة ﻏﻨﻴـﺔ ﺑﺎﻷزرق ﻣﺪﻣﺮاً ﺑﺸﻜﻞ ﺧﺎص ﻟﻌﻠـﻢ اﻟﻔﻠـﻚ ﺣﻴﺚ إن اﻷﻃﻮال ا ﻮﺟﻴﺔ اﻷﻗﴫ ﺗﺘﺒﻌﺜﺮ ﰲ اﻟﻐﻼف اﻟﺠﻮي ﺑﻜﻔـﺎ ءة أﻋـﲆ ﺑﻜﺜـ ﻣـﻦ اﻷﻃﻮال ا ﻮﺟﻴﺔ اﻷﻃﻮل إذ ﻳُﻘﺪﱠر أن اﻟﻀـﻮء اﻷزرق ﻋﻨﺪ 440 ﻧﺎﻧﻮﻣﱰ ﻳﺘﺒﻌﺜﺮ ﺑﻨﺤﻮ 2.5 ﻣﺮة أﻛﺜﺮ ﻣﻦ اﻟﻀﻮء اﻷﺧﴬ - اﻷﺻﻔﺮ ﻋﻨﺪ 550 ﻧﺎﻧﻮﻣﱰ وﻫﺬا ﻳﻌﻨﻲ أن ﻣﺼـﺒﺎح LED أﺑﻴﻀﺎً واﺣﺪاً ﻳﺴﻬﻢ ﺑﺸﻜﻞ ﻏ ﻣﺘﻨﺎﺳ ﺐ ﰲ ﻗﺒﺔ اﻟﺘﻮﻫﺞ اﻟﺴﻤﺎوي ا ﻨﺘﴩ ﻟﻮ ﻛﺎن ﺣﺘﻰ ﺗﺪﻓﻘﻪ اﻟﻀﻮﺋﻲ اﻟﻜﲇ أﻗﻞ ﻣﻦ ا ﺼﺒﺎح اﻟﺬي اﺳﺘُﺒﺪل ﺑﻪ وﻻ ﻳﻘﺘﴫ اﻷﻣﺮ ﻋﲆ اﻟﻨﻄﺎﻗﺎت اﻟﻌﻤﺮاﻧﻴﺔ ﻓﺎﻟﻀﻮء ا ﺘﺒ ﻌﺜﺮ ﻳﻤﻜﻦ أن ﻳﻨﺘﻘﻞ ﺴﺎﻓﺎت ﻃﻮﻳﻠﺔ ﻣـﺪﻫﻮر اً ﺟـﻮدة اﻟ ﺴـﻤﺎء ﺑﻌﻴﺪاً ﻋﻦ ا ﺼﺪر وو اﺻﻼً إﱃ ﻣﻨﺎﻃﻖ ﻧﺎﺋﻴﺔ ﻛﺎﻧﺖ ﺗُﻌﺪ آﻣﻨﺔ ﺳﺎﺑﻘﺎً . ﻟﺬﻟﻚ ﻟﻢ ﻳﻐﺐ اﻷﺛـﺮ ا ﺘﺰاﻳﺪ ﻟﻠﺘﻮﻫﺞ اﻟﺴﻤﺎوي اﻻﺻﻄﻨﺎﻋﻲ ﻋـﻦ ا ﺠﺘﻤﻊ اﻟﻔﻠﻜﻲ، إذ ﺑﺎﺗـﺖ ﺣﺘـﻰ ا ﺮاﺻـﺪ ا ﺠﺘﻤﻊ اﻟﻔﻠﻜـﻲ إذ ﺑﺎﺗـﺖ ﺣﺘـﻰ ا ﺮاﺻـﺪ اﻷرﺿﻴﺔ اﻟﻜﱪى ﻣﺜﻞ ﻣﺮﺻﺪ ﻓ ا ﳼ روﺑ ﻋﲆ ﻗﻤﺔ ﺟﺒﻞ ﺳ و ﺑﺎﺗﺸﻮن واﻟﺘﻠﺴـﻜﻮب اﻟﻜﺒ ﺟﺪاً ﻋﲆ ﻗﻤﺔ ﺟﺒﻞ ﺳ و ﺑﺎراﻧـﺎل ﰲ ﺗﺸﻴﲇ ﻣﺘﺄﺛﺮة ﺑﺎﻟﺘﻠﻮث اﻟﻀﻮﺋﻲ ﻣﻊ ﻋﻮاﻗﺐ ﺷﺪﻳﺪة ﻋﲆ ﻛﻔﺎءﺗﻬﺎ وﻣﺨﺮﺟﺎﺗﻬﺎ اﻟﻌﻠﻤﻴﺔ . ﺗﻌﻤﻞ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﻜﺒـ ة ﺑـﺎﻟﻘﺮب ﻣـﻦ ﺣﺪود ﻓﻴﺰﻳﺎﺋﻴﺔ وﺗ ﻘﻨﻴـﺔ ﻗﺼـﻮى وﺗﻌﺘﻤـﺪ ﺑﺮاﻣﺞ اﻟﺘﺼـﻮﻳﺮ واﺳـﻊ ا ﺠـﺎل وﻣﺴـﻮح ا ﺠﺎل اﻟﺰﻣﻨﻲ ﻋﲆ ﺧﻠﻔﻴﺎت ﺳﻤﺎء ﻣﻈﻠﻤـﺔ وﻣﺴﺘﻘﺮة ﻟﺮﺻﺪ اﻹﺷﺎرات اﻟ اﻟ ﻜﻮﻧﻴﺔ ﺨﺎﻓﺘﺔ ﺘﴩة ـﻨاو وﻣﻊ ازدﻳـﺎد ﺳـﻄﻮع اﻟ ﺴـﻤﺎء ﻳﺼﺒﺢ اﻟﺘﺄﺛ ﻋـﲆ اﻟﻨـﺎﺗﺞ اﻟﻌﻠﻤـﻲ أﻣـﺮاً ﺣﺘﻤﻴﺎً ﺧﺎﺻﺔً ﰲ اﻟﺪراﺳﺎت اﻟﺘﻲ ﺗ ﺴـﺘﻬﺪف ﻇﻮاﻫﺮ ذات ﺳـﻄﻮع ﺳـﻄﺤﻲ ﻣـﻨﺨﻔﺾ ﺣﻴﺚ ﺗﻨﺨﻔﺾ ﻧﺴﺒﺔ اﻹﺷﺎرة إﱃ اﻟﻀـﺠﻴﺞ وﺗـﺰداد ﺻـﻌﻮﺑﺔ ا ﻌﺎﻟﺠـﺔ اﻟﻔﻮﺗﻮﻣﱰﻳ ـﺔ اﻟﺪﻗﻴﻘﺔ واﺳﺘﺨﻼص اﻟﺒﻨﻰ اﻟﻀﻌﻴﻔﺔ . - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 6