Free Astronomy Magazine March-April 2026 ARABIC VERSION

Faint structures such as galactic halos, tidal streams, and the diffuse outskirts of galaxies are among the most challenging targets, as their signals lie only marginally above the natural sky background. Blue-rich skyglow amplifies that background unevenly, introducing gradients and spatialvariationsthatcomplicatecal- ibration and background modelling. Toaddtothechallenge,thespectral lines from white LEDs, unlike those from sodium lamps, contaminate nearly the entire visible spectrum, reducing contrast across all wave- lengthssimultaneously.Thisso-called “broadband pollution” makes sky subtraction, spectroscopic, and pho- tometric calibration far more com- plex, even with sophisticated post- processing techniques, with a signif- icant impact on faint emission and absorption features critical to extra- galactic and cosmological studies. Mostoftheseadverseeffectscannot befullymitigatedthroughpost-pro- cessingalone:advancedcalibration pipelinesandmodellingtechniques canonlyreducecontaminationtoa certainextent,butwheninforma- tion is lost in the glowing back- ground, there is not much that as- tronomers can do to restore it. This brings us to another paradox, because if on one hand astronomy is entering an era of ambitious surveys and precision measurements, with a renewed public interest and billions in investments, on the other hand light pollution trends are out of con- trol and risk limiting the scientific output of major ground-based in- struments. The impact on survey strategies and budget is not negligible either: it is estimated that a 10% increase in sky brightness requires a comparable increase in integration time to re- cover the lost signal-to-noise ratio. Formulti-billion-dollarobservatories with decades-long programmes, this translates into months of additional survey time, with a significant budg- etary impact. Concerns about light pollution are mounting within both the profes- sionalandamateurastronomycom- munity, with major organisations andobservatoriesrisingworryabout thepaceandthetrajectoryofout- door lighting transition. Several statements and reports from inter- nationalbodiesarepointingout that the sky is a shared scientific re- source that must be preserved for future generations. Particularly at a time when peculiar proposals have emerged, envisioning fleets of satel- lites acting as orbital mirrors to illu- minateselectedregionsaftersunset. Luckily, this growing awareness is now driving public and political dis- cussions across Europe and North America, as astronomers team up with ecologists and urban plannersto call for new and more stringent policiesthatprioritisenecessityover excess. Whilethereisalwaysmorethatcan be done, the encouraging reality is that light pollution, unlike other formsofpollution,isoneofthefew large-scaleenvironmentalproblems for which we have effective solu- tions: artificial light can be dimmed, redirected, and switched off. Tar- geted solutions, smart lighting de- sign, and awareness campaigns can quicklygiveustheskyback,without sacrificingfunctionalityorsafety. ■ MARCH-APRIL2026 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 9 ﺗُﻌﺪّ اﻟ ﻬﻴﺎﻛﻞ اﻟﺨﺎﻓﺘﺔ ﻣﺜﻞ ﻫـﺎﻻت ا ﺠـﺮات واﻟ ﺘﻴﺎرات ا ﺪﻳﺔ واﻷﻃﺮاف ا ﻨﺘﴩة ﻟﻠﻤﺠﺮات ﻣﻦ ﺑـ أﺻـﻌﺐ اﻷﻫـﺪاف رﺻـﺪ اً إذ ﺗﻘـﻊ إﺷﺎراﺗﻬﺎ ﻓﻘﻂ ﻋﲆ ﺣﺪود ﺧﻠﻔﻴـﺔ اﻟﺴـﻤﺎء اﻟﻄﺒﻴﻌﻴﺔ . ﻳﺰﻳﺪ اﻟﺘـﻮﻫﺞ اﻟﺴـﻤﺎوي اﻟﻐﻨـﻲ ﺑﺎﻷزرق ﻣﻦ ﻫﺬه اﻟﺨﻠﻔﻴﺔ ﺑﺸﻜﻞ ﻏ ﻣﺘﺴﺎو ﺎً ﻣﺤﺪﺛ ﺗـﺪرﺟﺎت وﺗﺒﺎﻳﻨـﺎت ﻣﻜﺎﻧﻴـﺔ ﺗﻌﻘـﺪ ﻋﻤﻠﻴﺎت ا ﻌﺎﻳﺮة وﻧﻤﺬﺟـﺔ اﻟﺨﻠﻔﻴـﺔ وﻳﺰﻳـﺪ اﻷﻣﺮ ﺗﻌﻘﻴـﺪ اً ﺣﻘﻴﻘـﺔ أن ﺧﻄـﻮط اﻟﻄﻴـﻒ اﻟﺼﺎدرة ﻋﻦ ﻣﺼﺎﺑﻴﺢ LED اﻟﺒﻴﻀـﺎء ﻋـﲆ ﻋﻜﺲ ﺗﻠﻚ اﻟﻨﺎﺗﺠﺔ ﻋﻦ ﻣﺼﺎﺑﻴﺢ اﻟﺼـﻮدﻳﻮم ﺗﻠﻮث ﺗﻘﺮﻳﺒ ﺎً اﻟﻄﻴﻒ ا ﺮﺋﻲ ﺑﺎﻟﻜﺎﻣﻞ ﻣﺎ ﻳﻘﻠﻞ اﻟﺘﺒﺎﻳﻦ ﻋﱪ ﺟﻤﻴ ﻊ اﻷﻃﻮال ا ﻮﺟﻴﺔ ﰲ اﻟﻮﻗﺖ ﻧﻔ ﺴﻪ وﻳﻌﺮف ﻫﺬا ﺑﺎﺳﻢ " اﻟﺘﻠـﻮث ﻋـﺮﻳﺾ اﻟﻨﻄﺎق " وﻫﻮ ﻳﺠﻌﻞ ﻋﻤﻠﻴﺎت ﻃﺮح اﻟﺴـﻤﺎء وا ﻌﺎﻳﺮة اﻟﻄﻴﻔﻴﺔ واﻟﻔﻮﺗﻮﻣﱰﻳﺔ أﻛﺜﺮ ﺗﻌﻘﻴﺪاً ﺣﺘﻰ ﻣﻊ اﺳﺘﺨﺪام ﺗ ﻘﻨﻴﺎت ا ﻌﺎﻟﺠﺔ اﻟﺠﺪﻳﺪة ا ﺘﻘﺪﻣﺔ و ﻣﻊ ﺗﺄﺛ ﻛﺒ ﻋـﲆ اﻹﺷـﻌﺎﻋﺎت واﻻﻧﺒﻌﺎﺛـــﺎت اﻟﺨﺎﻓﺘـــﺔ واﻻﻣﺘﺼﺎﺻـــﻴﺔ اﻟﴬورﻳﺔ ﻟﻠﺪراﺳﺎت ﺧـﺎرج ا ﺠـﺮة وﻋﻠـﻢ اﻟﻜ . ﻮﻧﻴﺎت ﻣﻌﻈﻢ ﻫﺬه اﻟﺘﺄﺛ ات اﻟﺴـﻠﺒﻴﺔ ﻻ ﻳﻤﻜﻦ اﻟﺘﺨﻔﻴﻒ ﻣﻨﻬﺎ ﺑﺎﻟﻜﺎﻣـﻞ ﻣـﻦ ﺧـﻼل ا ﻌﺎﻟﺠﺔ اﻟﻼﺣﻘﺔ وﺣﺪﻫﺎ : ﻓﺨﻄﻮط ا ﻌﺎﻳﺮة ا ﺘﻘﺪﻣﺔ وﺗﻘﻨﻴﺎت اﻟﻨﻤﺬﺟﺔ ﻳﻤﻜﻨ ﻬـﺎ ﻓﻘـﻂ ﺗﻘﻠﻴﻞ اﻟﺘﻠﻮث إﱃ ﺣـﺪ ﻣﻌـ وﻟﻜـﻦ ﻋﻨـﺪﻣﺎ ــــــــــــــــــــــــــــــــــــ ﺗﻔﻘـﺪ ا ﻌﻠﻮﻣـﺎت ﰲ اﻟﺨﻠﻔﻴـﺔ ا ﺘﻮﻫﺠـﺔ ﻻ ﻳﻮﺟﺪ اﻟﻜﺜ ﻣﻤﺎ ﻳﻤ ﻜﻦ ﻟﻌﻠﻤﺎء اﻟﻔﻠﻚ ﻓﻌﻠـﻪ ﻻﺳﺘﻌﺎدﺗﻬﺎ وﻫﺬا ﻳﻘﻮدﻧﺎ إﱃ ﻣﻔﺎرﻗﺔ أﺧﺮى : ﺪﺧﻞ ﻳ ﻓﺒﻴﻨﻤﺎ اﻟﻔﻠـﻚ ﻋﻠﻢ واﻟﺮﺻـﺪ اﻟﻔﻠﻜـﻲ ا زﻣـﻦ ﺴـﻮﺣﺎت اﻟﻄﻤﻮﺣـﺔ واﻟﻘﻴﺎﺳـﺎت اﻟﺪﻗﻴﻘــ ﺔ ﻣــﻊ اﻫﺘﻤــﺎم ﻋــﺎم ﻣﺘﺠــﺪ د واﺳﺘﺜﻤﺎرات ﺑﻤﻠﻴﺎرات اﻟﺪوﻻرات ﻣﻦ ﺟﻬـﺔ أﺧﺮى ﺗﺘﺰاﻳﺪ ﻇﺎﻫﺮة اﻟﺘﻠﻮث اﻟﻀﻮﺋﻲ ﺑﺸﻜﻞ ﻳﻔﻮق اﻟﺴﻴﻄﺮة ﻣﻤﺎ ﻳﻬﺪد ﺑﺤﺪ ﻗﺪرة اﻷﺟﻬﺰة اﻷرﺿﻴﺔ اﻟﻜﱪى ﻋﲆ إﻧﺘﺎج ﻣﺨﺮﺟﺎت ﻋﻠﻤﻴﺔ ﻋﺎﻟﻴﺔ ا ﻟﺠﻮدة وﻻ ﻳﺴﺘﻬﺎن أﻳﻀ ﺎً ﺑﺘﺄﺛ ذﻟـﻚ ﻋﲆ اﺳﱰاﺗﻴﺠﻴﺎت ا ﺴـﻮ ﺣﺎت وا ﻴﺰاﻧﻴـﺎت : ﻓﻮﻓـﻖ اﻟﺘﻘــﺪﻳﺮات ﺗـ ﺆدي زﻳـﺎدة ﺳـﻄﻮع اﻟﺴـﻤﺎء ﺑﻨﺴـﺒﺔ 10 % إﱃ اﻟﺤﺎﺟـﺔ ﻟﺰﻳـﺎدة ﻣﻤﺎﺛﻠﺔ ﰲ زﻣﻦ اﻟﺘﻜﺎﻣـﻞ ﻻﺳـﺘﻌﺎدة ﻧﺴـ ﺒﺔ اﻹﺷﺎرة إﱃ اﻟﻀﻮﺿﺎء ا ﻔﻘـﻮدة وﺑﺎﻟﻨﺴـﺒﺔ ﻟﻠﻤﺮاﺻﺪ اﻟﺘﻲ ﺗﻜﻠﻔﺘﻬﺎ ﻣﻠﻴـﺎرات اﻟـﺪوﻻرات و ﻟﺪﻳﻬﺎ ﺑﺮاﻣﺞ ﺗﻤﺘﺪ ﻟﻌﻘﻮد ﻳﻌﻨﻲ ذﻟ ﻚ أﺷـﻬﺮاً إﺿﺎﻓﻴﺔ ﻣﻦ وﻗﺖ ا ﺴـﻮﺣﺎت ﻣـﻊ ﺗـﺄﺛ ات ﻣﺎﻟﻴﺔ ﻛ ﺒ ة ﻋﲆ ا ﻴﺰاﻧﻴﺔ . ﺗﺘﺰاﻳﺪ ا ﺨﺎوف ﺑﺸﺄن اﻟﺘﻠﻮث اﻟﻀﻮﺋﻲ داﺧﻞ ﻣﺠﺘﻤﻊ اﻟﻔﻠﻜﻴ ا ﺤﱰﻓ واﻟﻬﻮاة ﻋﲆ ﺣﺪ ﻮاءـﺳـ ﺣﻴـﺚ ﺑـﺪأت ا ﻨﻈﻤـﺎت وا ﺮاﺻـﺪ اﻟﻜﱪى ﺗﻌﺮب ﻋﻦ ﻗﻠﻘﻬﺎ ﺗﺠﺎه وﺗ ة وﻣﺴﺎر اﻟﺘﺤﻮل ﰲ اﻹﺿﺎءة اﻟﺨﺎرﺟﻴـﺔ . ﺗﺸـ ﻋـﺪة ــــــــــــــــــــــــــــــــــــ ﺑﻴﺎﻧﺎت وﺗﻘﺎرﻳﺮ ﺻﺎدرة ﻋﻦ ﻫﻴﺌﺎت دوﻟﻴﺔ إﱃ أن اﻟﺴﻤﺎء ﺗﻤﺜﻞ ﻣﻮرداً ﻋﻠﻤﻴﺎً ﻣﺸﱰﻛﺎً ﻳﺠﺐ اﻟﺤﻔﺎظ ﻋﻠﻴﻪ ﻟﻸﺟﻴﺎل اﻟﻘﺎدﻣﺔ وﻳـﺄﺗﻲ ﻫـﺬا ﺑﺸﻜﻞ ﺧﺎ ص ﰲ وﻗﺖ ﻇﻬﺮت ﻓﻴﻪ ﻣﻘﱰﺣﺎت ﻏﺮﻳﺒــﺔ ﺗﻄﺎﻟــﺐ ﺄﺳ ـﺎ ﺑ ﻃﻴﻞ ﻣ ـﻦ اﻷﻗﻤ ـﺎر اﻟﺼﻨﺎﻋﻴﺔ ﺗﻌﻤـﻞ ﻛ ﻤﺮاﻳـﺎ ﻣﺪارﻳـﺔ ﻹﺿـﺎءة ﻣﻨـ ﺎﻃﻖ ﻣﺤـﺪدة ﺑﻌـﺪ اﻟﻐــﺮوب ﻣــﺎ ﻳﺜ ـ ﺗﺴﺎؤﻻت ﺣﻮل اﻟﺤﺪود اﻷﺧﻼﻗﻴـﺔ واﻟﺒﻴﺌﻴـﺔ ﻻﺳﺘﺨﺪم اﻟﻀﻮء اﻻﺻﻄﻨﺎﻋﻲ . وﻟﺤﺴﻦ اﻟﺤﻆ ﻓﺈن اﻟﻮﻋﻲ ا ﺘﺰاﻳﺪ اﻵن ﻳﺪﻓﻊ اﻟﻨﻘﺎﺷـﺎت اﻟﻌﺎﻣـﺔ واﻟﺴﻴ ﺎﺳـﻴﺔ ﰲ أوروﺑـﺎ وأﻣﺮﻳﻜﺎ اﻟﺸﻤﺎﻟﻴﺔ ﺣﻴﺚ ﻳﺘﻌﺎون ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻣﻊ ﻋﻠﻤﺎء اﻟﺒﻴﺌﺔ وﻣﺨﻄﻄﻲ ا ﺪن ﻟﻠﺪﻋ ﻮة إﱃ ﺳﻴﺎﺳـﺎت ﺟﺪﻳـﺪة وأﻛﺜـﺮ ﴏاﻣـﺔ ﺗُﻌﻄـﻲ اﻷوﻟﻮﻳﺔ ﻟﻠﺤﺎﺟﺔ ﻋﲆ اﻹﴎاف . وﻋﲆ اﻟﺮﻏﻢ ﻣﻦ أ ن ﻫﻨﺎك داﺋﻤ ﺎً ا ﺰﻳـﺪ ﻣﻤـﺎ ﻳﻤﻜﻦ ﻋﻤﻠﻪ ﻓﺈن اﻟﺤﻘﻴﻘﺔ ا ﺸﺠﻌﺔ ﻫـﻲ أن اﻟﺘﻠﻮث اﻟﻀﻮ ﺋﻲ ﻋﲆ ﻋﻜﺲ أﺷـﻜﺎل اﻟﺘﻠـﻮث اﻷﺧﺮى ﻳﻌﺪ ﻣـﻦ ا ﺸـﺎﻛﻞ اﻟﺒﻴﺌﻴـﺔ واﺳـﻌﺔ اﻟﻨﻄﺎق اﻟﺘﻲ ﻟﺪﻳﻨﺎ ﺣﻠﻮل ﻓﻌ ﺎﻟـﺔ ﻟﻬـﺎ ﺣﻴـﺚ ﻳﻤﻜﻦ ﺗﺨﻔﻴﺾ ﺷـﺪة اﻟﻀـﻮء اﻻﺻـﻄﻨﺎﻋﻲ إﻋﺎدة ﺗﻮﺟﻴﻬﻪ أو إﻳﻘـﺎف ﺗﺸـﻐﻴﻠﻪ وﻳﻤﻜـﻦ ﻟﻠﺤﻠﻮل ا ﺴﺘﻬﺪﻓﺔ وﺗﺼﻤﻴﻢ اﻹﺿﺎءة اﻟﺬﻛﻲ وﺣﻤﻼت اﻟﺘ ﻮﻋﻴ ﺔ أن ﺗ ﻌﻴﺪ اﻟﺴﻤﺎء إﻟﻴﻨـﺎ دون اﻟﺘﻀ ﺤﻴﺔ ﺑﺎﻟﻮﻇﺎﺋﻒ اﻟﻌﻤﻠﻴﺔ أو اﻟﺴﻼﻣﺔ . - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 6