Free Astronomy Magazine November-December 2024 ARABIC VERSION

ground,orCOB–providedawayto add up all the light generated by galaxiesoverthelifetimeoftheuni- verse before NASA’s Hubble Space Telescope and James Webb Space Telescopecouldseethefaintback- ground galaxies directly. IntheHubbleandJamesWebbtel- escope era, astronomersmeasure the COB to detect light that might comefromsourcesotherthanthese known galaxies. But measuring the totallightoutputoftheuniverseis extremely difficult from Earth or anywhereintheinnersolarsystem. “Peoplehavetriedoverandoverto measureitdirectly,butinourpart ofthesolarsystem,there’sjusttoo much sunlight and reflected inter- planetarydustthatscattersthelight around into a hazy fog that ob- scures the faint light from the dis- tant universe,” said Tod Lauer, a New Horizons co-investigator, as- tronomer from the National Science Foundation NOIRLab in Tucson, Ari- zona, and a co-author of the new paper.“ Allattemptstomeasurethe strength of the COB from the inner solarsystemsufferfromlargeuncer- tainties.” EnterNewHorizons,billionsofmiles along its trek beyond the planets, now deep in the Kuiper Belt and headed toward interstellar space. Latelastsummer,fromadistance57 times farther from the Sun than Earth, New Horizons scanned the universe with its Long Range Re- connaissance Imager (LORRI), col- lectingtwo-dozenseparateimaging fields. LORRI itself was intentionally shielded from the Sun by the main body of the spacecraft – keeping eventhedimmestsunlightfromdi- rectly entering the sensitive camera – and the target fields were posi- tioned away from the bright disk and core of the Milky Way and nearby bright stars. The New Horizons observersused other data, taken in the far-infrared by the European Space Agency’s Planck mission, of fields with a range in dust density to calibrate thelevelofthosefar-infraredemis- sionstothelevelofordinaryvisible light. This allowed them to accu- rately predict and correct for the presence of dust-scattered Milky Way light in the COB images – a techniquethatwasnotavailableto themduringa2021testCOBobser- vation run with New Horizons in which they underestimatedthe amount of dust-scattered light and overestimatedexcesslightfromthe universe itself. Butthistimearound,afteraccount- ing for all known sources of light, such as background stars and light scattered by thin clouds of dust withintheMilkyWaygalaxy,there- searchersfoundtheremaininglevel of visible light was entirely consis- tentwiththeintensityoflightgen- eratedbyallgalaxiesoverthepast 12.6billionyears. “The simplest interpretation is that the COB is completely due to galax- ies,” Lauer said. “Looking outside the galaxies, we find darkness there and nothing more.” “Thisnewlypublishedworkisanim- portant contribution to fundamen- tal cosmology, and really something that could only be done with a far- awayspacecraftlikeNewHorizons,” said New Horizons Principal Investi- gator Alan Stern, of the Southwest Research Institute in Boulder, Col- orado. “And it shows that our cur- rent extended mission is making important scientific contributionsfar beyond the original intent ofthis planetary mission designed to make the first close spacecraft ex- plorations of Pluto and Kuiper Belt objects.” Launched in January 2006, New Horizons made the historic recon- naissance of Pluto and its moons in July 2015, before giving humankind its first close-up look at a planetary building block and Kuiper Belt ob- ject,Arrokoth,inJanuary2019.New Horizons is now in its second ex- tended mission, imaging distant Kuiper Belt objects, characterizing the outer heliosphere of the Sun,and making important astrophysical observations from its unmatched vantage point in the farthest re- gionsofthesolarsystem.     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 33 رﺳــــــــﻢ ﺗﺨ ﻠــــــــﻲ ﻟ ﻠﻤﺴــــــــ ﺎر اﻟﻔﻀــــــــﺎ ﺋﻲ ﻧﻴــــــــﻮ ﻫــــــــﻮراﻳﺰوﻧﺰاﻟﺘــــــــﺎﺑﻊ ﻟﻮ ﺎﻟــــــــﺔ ﻧﺎﺳــــــــﺎ ــــــــﺔ اﻟﻔﻀــــــــﺎء اﻣــــــــﺎمﺧﻠﻔ اﻟﻌﻤﻴــــــﻖ ﻋﻠـــــــﻰ ــــــﺎرا ﺘﺴـــــــﺎﻣﺔ ﻌــــــﺪ أﻛـــــــ ﻣـــــــﻦ ﻣﻠ 7.3 ــــــﺎرﻛ ﻠـــــــﻮﻣ ﻣﻠ ﻣـــــــﻦ اﻷرض ﻌــــــ اﻟﻤﺴـــــــ ﺎر ﻧﻴـــــــﻮ ﻫـــــﻮراﻳﺰوﻧﺰ ﻣﻨﻄﻘـــــﺔ ﻣـــــﻦ اﻟﻨﻈــــــﺎم اﻟﺸﻤﺴـــــﻲ - ـــــﺔ ﻣــــــﻦ اﻟﺸـــــﻤﺲ ﻟﺘﻘـــــﺪ ﻢ أﻇﻠـــــﻢﺳــــــﻤﺎء ﻣﺴـــــﺎﻓﺔ ﺎﻓ ﻣﺘﺎﺣــــــﺔ ﻷي ﺗﻠﺴــــــ ﻮب ﻣﻮﺟــــــﻮد - وﺗــــــﻮﻓ ﻧﻘﻄــــــﺔ رﺻــــــﺪ ــــــﺎس اﻟﺴــــــﻄﻮع ﻓﺮ ــــــﺪة ﻤﻜــــــﻦ ﻣــــــﻦﺧﻼﻟﻬــــــﺎ ﻗ اﻟ ﻠ ﻲ ﻟﻠ ﻮن اﻟ ﻌ ﺪ . ﻘﻊ اﻟﻤﺴﺎراﻟﻤ ﻮن ﻣﻦ ﻣﺠﺮة در اﻟﺘ ﺎﻧﺔ ﻓﻲ اﻟ ـ . ﺨﻠﻔ ﺔ ] NASA,APL,SwRI,SergeBrunier(ESO),MarcPostman(STScI),DanDurda [ ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4 ﻣﺪار ﻋﻤﺮ اﻟﻜﻮن ﻗﺒﻞ أن ﻳـﺘﻤﻜﻦ ﺗﻠﺴـﻜﻮب ﻫﺎﺑــﻞ اﻟﻔﻀــﺎﺋﻲ اﻟﺘــﺎﺑﻊ ﻟﻮﻛﺎﻟــﺔ ﻧﺎﺳــﺎ وﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ ﻣﻦ رؤﻳﺔ ا ﺠﺮات اﻟﺨﺎﻓﺘﺔ اﻟﺨﻠﻔﻴﺔ ﺑﺸﻜﻞ ﻣﺒﺎﴍ . ﻳﻘﻴﺲ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﰲ ﻋﴫ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ وﺟﻴﻤﺲ وﻳﺐ اﻟﺨﻠﻔﻴﺔ اﻟﺒـﴫﻳﺔ اﻟﻜ ﻮﻧﻴـﺔ ﻟﻠﻜﺸﻒ ﻋﻦ اﻟﻀـﻮء اﻟـﺬي ﻗـﺪ ﻳـﺄﺗﻲ ﻣـﻦ ﻣﺼﺎدر أﺧﺮى ﻏ ﻫﺬه ا ﺠـﺮات ا ﻌﺮوﻓـﺔ وﻟﻜﻦ ﻗﻴﺎس إﺟﻤﺎﱄ اﻟﻨﺎﺗﺞ اﻟﻀﻮﺋﻲ ﻟﻠﻜـﻮن ﺻﻌﺐ ﻟﻠﻐﺎﻳﺔ ﻣﻦ اﻷرض أو ﰲ أي ﻣﻜـﺎن ﰲ اﻟﻨﻈﺎم اﻟﺸﻤﴘ اﻟﺪاﺧﲇ . ﻗﺎل ﺗﻮد ﻻور أﺣـﺪ ا ﺤﻘﻘـ ا ﺸـﺎرﻛ ﰲ ﻣﴩوع ﻧﻴﻮ ﻫﻮراﻳﺰوﻧﺰ وﻋﺎﻟﻢ اﻟﻔﻠـﻚ ﻣـﻦ ﻣﺨﺘﱪ ب ﻧﻮﻳﺮﻻ اﻟﺘﺎﺑﻊ ﻟﻠﻤﺆﺳﺴﺔ اﻟﻮﻃﻨﻴـﺔ ﻟﻠﻌﻠﻮم وا ﺆﻟﻒ ا ﺸﺎرك ﰲ اﻟﺒﺤـﺚ اﻟﺠﺪﻳـﺪ " ﻟﻘﺪ ﺣﺎول اﻟﻨﺎس ﻣـﺮارًا وﺗﻜـﺮارًا ﻗﻴﺎﺳـﻪ " ﻟﻘﺪ ﺣﺎول اﻟﻌﻠﻤﺎء اً ﻣﺮار اً وﺗﻜـﺮار ﻗﻴﺎﺳـﻪ ﺑﺸﻜﻞ ﻣﺒﺎﴍ وﻟﻜﻦ ﰲ ﺟﺰءﻧﺎ ﻣـﻦ اﻟﻨﻈـﺎم اﻟﺸﻤﴘ ﻫﻨﺎك اﻟﻜﺜ ﻣـﻦ ﺿـﻮء اﻟﺸـﻤﺲ واﻟﻐﺒﺎر اﻟﻜﻮﻛﺒﻲ ا ﻨﻌﻜﺲ اﻟﺬي ﻳﻨﺜﺮ اﻟﻀﻮء ﺣﻮﻟﻪ ﰲ ﺿـﺒﺎب ﻏـﺎﻣﺾ ﻳﺤﺠـﺐ اﻟﻀـﻮء اﻟﺨﺎﻓﺖ اﻟﻘﺎدم ﻣﻦ اﻟﻜﻮن اﻟﺒﻌﻴﺪ . ﺗﻌﺎﻧﻲ ﺟﻤﻴﻊ ا ﺤﺎوﻻت ﻟﻘﻴﺎس ﻗﻮة اﻟﺨﻠﻔﻴﺔ اﻟﺒـﴫﻳﺔ اﻟﻜﻮﻧﻴﺔ ﻣـﻦ اﻟﻨﻈـﺎم اﻟﺸـ ﻤﴘ ـ اﻟﺪاﺧﲇ ﻣﻦ ﻋﺪم اﻟﻴﻘ اﻟﻜﺒ ." ﻗﻄـﻊ ا ﺴـﺒﺎر ﻧﻴـﻮ ﻫــﻮراﻳﺰوﻧﺰ ﻣﺴـﺎﻓﺔ ﻣﻠﻴﺎرات اﻷﻣﻴﺎل ﻋﲆ ﻃﻮل رﺣﻠﺘﻪ إﱃ ﻣ ﺎ وراء اﻟﻜﻮاﻛﺐ وﻫ ﻮ اﻵن ﰲ أﻋﻤـﺎق ﺣـﺰام ﻛـﺎﻳﱪ ﻳو ﺘﺠﻪ ﻧﺤﻮ اﻟﻔﻀﺎء ﺑ اﻟﻨﺠﻮم . ﰲ أواﺧﺮ اﻟﺼﻴﻒ ا ﺎﴈ وﻣﻦ ﻣﺴﺎﻓﺔ أﺑﻌـﺪ ﺑـ 57 ﻣﺮة ﻋﻦ اﻟﺸـﻤﺲ ﻣـﻦ اﻷرض، ﻗـﺎم ا ﺴـﺒﺎر ﻧﻴـﻮ ﻫـﻮراﻳﺰوﻧﺰ ﺑﻤﺴـﺢ اﻟﻜـﻮن ﺑﺎﺳﺘﺨﺪام ﺟﻬـﺎز اﻟﺘﺼـﻮﻳﺮ اﻻﺳـﺘﻄﻼﻋﻲ ﺑﻌﻴﺪ ا ﺪى ﻟﻮري ) وﺟﻤﻊ ( ﻋﴩات اﻟﺤﻘﻮل اﻟﺘﺼﻮﻳﺮﻳﺔ ا ﻨﻔﺼﻠﺔ . ﺗﻢ ﺣﺠﺐ ﺟﻬﺎز اﻟﺘﺼﻮﻳﺮ اﻻﺳﺘﻄﻼﻋﻲ ﺑﻌﻴﺪ ا ـﺪى ﻋـﻦ اﻟﺸـﻤﺲ ﻋـﻦ ﻃﺮﻳـﻖ اﻟﺠﺴـﻢ اﻟﺮﺋﻴﴘ ﻟﻠﻤﺮﻛﺒﺔ اﻟﻔﻀﺎﺋﻴﺔ ﻣﻤﺎ ﻣﻨﻊ ﺣﺘـﻰ أﺿﻌﻒ ﺿﻮء اﻟﺸﻤﺲ ﻣﻦ اﻟﺪﺧﻮل ﻣﺒـﺎﴍة إﱃ اﻟ ﻜﺎﻣ ا اﻟﺤﺴﺎﺳﺔ وﺗﻢ وﺿـﻊ اﻟﺤﻘـﻮل ا ﺴﺘﻬﺪﻓﺔ ﺑﻌﻴﺪ اً ﻋﻦ اﻟﻘﺮص اﻟﺴﺎﻃﻊ وﻧﻮاة درب اﻟﺘﺒﺎﻧﺔ واﻟﻨﺠﻮم اﻟﺴﺎﻃﻌﺔ اﻟﻘﺮﻳﺒﺔ . ﻟﻘﺪ اﺳﺘﺨﺪم ﻣ ﺮاﻗﺒﻮ ﻧﻴﻮ ﻫﻮراﻳﺰوﻧﺰ ﺑﻴﺎﻧﺎت أﺧﺮى ﺗﻢ اﻟﺘﻘﺎﻃﻬﺎ ﰲ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﺒﻌﻴﺪة ﺑﻮاﺳﻄﺔ ﻣﻬﻤﺔ ﺑﻼﻧﻚ اﻟﺘﺎﺑﻌﺔ ﻟﻮﻛﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑﻴﺔ ﻟﻠﺤﻘﻮل ذات ﻧﻄﺎق ﻛﺜﺎﻓﺔ اﻟﻐﺒﺎر ﻌﺎﻳﺮة ﻣﺴـﺘﻮى اﻧﺒﻌﺎﺛـﺎت اﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﺒﻌﻴﺪ ة إﱃ ﻣﺴـﺘﻮى اﻟﻀـﻮء ا ﺮﺋﻲ اﻟﻌﺎدي وﻗﺪ ﺳﻤﺢ ﻟ ﻬﻢ ﻫـﺬا ﺑـﺎﻟﺘﻨﺒﺆ ﺑﺪﻗﺔ وﺗﺼﺤﻴﺢ وﺟـﻮد ﺿـﻮء درب اﻟﺘﺒﺎﻧـﺔ ا ﺒﻌﺜﺮ ﺑﺎﻟﻐﺒﺎر ﰲ ﺻﻮر اﻟﺨﻠﻔﻴﺔ اﻟﺒــﴫﻳﺔ اﻟﻜﻮﻧﻴﺔ وﻫﻲ ﺗﻘﻨﻴﺔ ﻟﻢ ﺗﻜـﻦ ﻣﺘﺎﺣـﺔ ﻟﻬـﻢ أﺛﻨﺎء ﻋﻤﻠﻴـﺔ ﻣﺮاﻗﺒـﺔ اﻟﺨﻠﻔﻴـﺔ اﻟﺒــﴫﻳﺔ اﻟﻜﻮﻧﻴﺔ اﻟﺘﺠﺮﻳﺒﻴﺔ ﻟﻌﺎم ٢٠٢١ اﻟﺘﻲ أﺟﺮﻳﺖ ﻣﻊ ﻧﻴﻮ ﻫﻮراﻳﺰوﻧﺰ ﺣﻴﺚ ﻗﻠﻠﻮا ﻣـﻦ ﺗﻘـﺪﻳﺮ اﻟﻜﻮﻧﻴﺔ اﻟﺘﺠﺮﻳﺒﻴﺔ ﻟﻌﺎم 2021 اﻟﺘﻲ أﺟﺮﻳﺖ ﻣﻊ ا ﺴﺒﺎر ﻧﻴﻮ ﻫﻮراﻳﺰوﻧﺰ ﺣﻴﺚ ﻗﻠﻠﻮا ﻣـﻦ ﺗﻘﺪﻳﺮ ﻛﻤﻴﺔ اﻟﻀﻮء ﺑﺎﻟﻐﺒﺎر ا ﺸﺘﺖ وﺑﺎﻟﻐﻮا ﰲ ﺗﻘﺪﻳﺮ اﻟﻀﻮء اﻟﺰاﺋﺪ ﻣﻦ اﻟﻜﻮن ﻧﻔﺴﻪ . ﻟﻜﻦ ﻫﺬه ا ﺮة وﺑﻌﺪ اﻷﺧﺬ ﰲ اﻻ ﻋﺘﺒﺎر ﺟﻤﻴﻊ ﻣﺼـﺎدر اﻟﻀـﻮء ا ﻌﺮوﻓـﺔ ﻣ ﺜـﻞ اﻟﻨﺠـﻮم اﻟﺨﻠﻔﻴﺔ واﻟﻀﻮء ا ﺸﺘﺖ ﺑﻮاﺳـﻄﺔ ﺳـﺤﺐ اﻟﻐﺒﺎر اﻟﺮﻗﻴﻘﺔ داﺧـﻞ ﻣﺠـﺮة در ب اﻟﺘﺒﺎﻧـﺔ وﺟﺪ اﻟﺒـﺎﺣﺜﻮن أن ا ﺴـ ﺘﻮى ا ﺘﺒﻘـﻲ ﻣـﻦ اﻟﻀﻮء ا ﺮﺋﻲ ﻛﺎن ﻣﺘﺴﻘ ﺎً ﺎً ﺗﻤﺎﻣ ﻣـﻊ ﺷـﺪة اﻟﻀﻮء اﻟ ﺬي ﺗﻮﻟﺪه ﺟﻤﻴﻊ ا ﺠﺮات ﻋﲆ ﻣﺪار اﻟـ 12.6 ﻣﻠﻴﺎر ﺳﻨﺔ ا ﺎﺿﻴﺔ . ﻗﺎل ﻟﻮر " : اﻟﺘﻔﺴ اﻷﺑﺴﻂ ﻫﻮ أن اﻟﺨﻠﻔﻴﺔ اﻟﺒ ــﴫﻳﺔ اﻟﻜﻮﻧﻴــﺔ ﻳﺮﺟــﻊ ﺑﺎﻟﻜﺎﻣــﻞ إﱃ ا ﺠﺮا ت و ﺑﺎﻟﻨﻈﺮ ﺧﺎرج ا ﺠﺮات ﻧﺠﺪ اﻟﻈﻼم ﻫﻨﺎك وﻻﳾء أﻛﺜﺮ ." ﻗﺎل آﻻن ﺳﺘ ن اﻟﺒﺎﺣﺚ اﻟﺮﺋﻴﴘﰲ ﻣﴩوع ا ﺴﺒﺎر ﻧﻴﻮ ﻫﻮراﻳﺰوﻧﺰ ﻣﻦ ﻣﻌﻬـﺪ ﺳـﺎوث وﻳﺴﺖ ﻟﻸﺑﺤـﺎث ﰲ ﻣﺪﻳﻨـﺔ ﺑﻮﻟـﺪر ﺑﻮﻻﻳـﺔ ﻟﻮرادو ﻛﻮ " : إن ﻫﺬا اﻟﻌﻤﻞ ا ﻨﺸـﻮر ﺣـﺪﻳﺜ ﺎً ﻫـﻮ ﻣﺴـﺎﻫ ﻤﺔ ﻣﻬﻤـﺔ ﰲ ﻋﻠـﻢ اﻟﻜﻮﻧﻴـﺎت اﻷﺳﺎﳼ وﻫ ﻮ ﳾء ﻻ ﻳﻤﻜﻦ ا ﻟﻘﻴـﺎم ﺑـﻪ إﻻ ﺑﻤﺮﻛﺒﺔ ﻓﻀﺎﺋﻴﺔ ﻣﺜﻞ ا ﺴﺒﺎر ﻧﻴﻮ ﻫﻮراﻳﺰون وﻫﺬ ا ﻳُﻈﻬِﺮ أن ﻣﻬﻤﺘﻨـﺎ ا ﻮﺳـﻌﺔ اﻟﺤﺎﻟﻴـﺔ ﺗُﻘﺪﱢم ﻣﺴـﺎﻫﻤﺎت ﻋﻠﻤﻴـﺔ ﻣﻬﻤـﺔ ﺗﺘﺠـﺎوز ﺑﻜﺜ اﻟﻬﺪف اﻷﺻﲇ ﻟﻬﺬه ا ﻬﻤﺔ اﻟﻜﻮﻛﺒﻴـﺔ و ا ﺼﻤﻤﺔ ﻹﺟﺮاء أول اﺳﺘﻜﺸﺎﻓﺎت ﻗﺮﻳﺒـﺔ ﺮﻛﺒـﺔ ﻓﻀـﺎﺋﻴﺔ ﻟﻠﻜﻮﻛـﺐ اﻟﻘـﺰم ﻟﺒﻠﻮﺗـﻮ وأﺟﺴﺎم ﺣﺰام ﻛﺎﻳﱪ ." أُﻃﻠﻘﺖ وﻛﺎﻟﺔ ﻧﺎﺳﺎ ا ﺴﺒﺎر ﻧﻴﻮ ﻫـﻮراﻳﺰوﻧﺰ ﰲ ﻳﻨﺎﻳﺮ 2006 ﻗﺎﻣﺖ و ﺑﺎﺳﺘﻜﺸﺎف ﺗﺎرﻳﺨﻲ ﻟ ﻠﻜﻮﻛـﺐ اﻟﻘـﺰم ﺑﻠﻮﺗـﻮ وأﻗﻤـﺎره ﰲ ﻳﻮﻟﻴـﻮ 2015 ﻗﺒﻞ أن ﺗﻤﻨﺢ اﻟﺒﴩﻳﺔ أول ﻧﻈﺮة ﻋﻦ ﻗﺮب ﻋﲆ ﻛ ﺘﻠﺔ ﺑﻨﺎء ﻛﻮﻛﺒﻴﺔ وﺟﺴـﻢ ﺣـﺰام ﻛﺎﻳﱪ ا ﺴـﻤﻰ ) أروﻛــﻮث وذﻟ ـﻚ ( ﰲ ﻳﻨ ـﺎﻳﺮ 2019 . ا ﺴــﺒﺎر ﻧﻴ ـﻮ ﻫ ـﻮراﻳﺰوﻧﺰ اﻵن ﰲ ﻣﻬﻤﺘــﻪ ا ﻮﺳﻌﺔ اﻟﺜﺎﻧﻴﺔ اﻟﺘﻲ ﻗﺮرﺗﻬـﺎ وﻛﺎﻟـﺔ ﻧﺎﺳـﺎ ﻳ ﺣﻴﺚ ﺑ ﻘـﻮم ﺘﺼـﻮﻳﺮ أ ﺣـﺰام ﰲ ﺟﺴـﺎم ﻻ ﻛﺎﻳﱪ اﻟﺒﻌﻴﺪة وﺗﻮﺻﻴﻒ اﻟﺠﺰء اﻟﺨﺎرﺟﻲ ﻣﻦ ﻓﻘﺎﻋﺔ اﻟﻬﻴﻠﻮﺳﻔ اﻟﺘـﻲ ﺗﺤـﻴﻂ ﺑﻨﻈﺎﻣﻨـﺎ اﻟﺸﻤﴘ وإﺟﺮاء أرﺻـﺎد ﻓﻴﺰﻳﺎﺋﻴـﺔ ﻓﻠﻜﻴـﺔ ﻣﻬﻤﺔ ﻣ ﻦ ﻧﻘﻄﺔ ﻣﺮاﻗﺒﺔ اﺳﺘﺜﻨﺎﺋﻴﺔ ﰲ أﺑﻌـﺪ ﻣﻨﺎﻃﻖ اﻟﻨﻈﺎم اﻟﺸﻤﴘ .