Free Astronomy Magazine November-December 2022 ARABIC VERSION

N by NASA/ESA/CSA Hannah Braun Christine Pulliam ASA’s James Webb Space Tele- scope shows off its capabili- ties closer to home with its first image of Neptune. Not only has Webb captured the clearest view of this distant planet’s rings in more than 30 years, but its cameras reveal the ice giant in a whole new light. Most striking in Webb’s new image is the crisp view of the planet’s rings – some of which have not been de- tected since NASA’s Voyager 2 be- came the first spacecraft to observe Neptune during its flyby in 1989. In addition to several bright, narrow rings, the Webb image clearly shows Neptune’s fainter dust bands. “It has been three decades since we last saw those faint, dusty bands, and this is the first time we’ve seen them in the infrared,” notes Heidi Hammel, a Neptune system expert and interdisciplinary scientist for Webb. Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune. Neptune has fascinated researchers since its discovery in 1846. Located 30 times farther from the Sun than Earth, Neptune orbits in the remote, dark region of the outer solar sys- tem. At that extreme distance, the Sun is so small and faint that high noon on Neptune is similar to a dim twilight on Earth. NOVEMBER-DECEMBER 2022 ﺗﻠﺴ ﻮبو ﺐ ﻠﺘﻘﻂأوﺿﺢ ﺻﻮرة ﻟـﺤﻠﻘﺎت ﻧ ﺘﻮن ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٤٤ : ﻘﻠﻢ ﺑﻮﻟ ﺎم ﻫﺎﻧﺎ ﺑﺮاون و ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﻗﺪراﺗﻪ ﻣﻦ ﺧﻼل اﻟﺼﻮرة اﻷوﱃ ﻟﻜﻮﻛﺐ ﻧﺒﺘﻮن . ﻟﻢ ﻳﻘﺘﴫ اﻷﻣﺮ ﻋﲆ اﻟﺘﻘـﺎط أوﺿﺢ ﻣﺸﻬﺪ ﻟﺤﻠﻘﺎت ﻫﺬا اﻟﻜﻮﻛـﺐ اﻟﺒﻌﻴـﺪ ﻣﻨـﺬ أﻛﺜـﺮ ﻣـﻦ ٣٠ ﻋﺎﻣًـﺎ وﻟﻜـﻦ ﻛﺎﻣ اﺗـﻪ ﺗﻜﺸﻒ ﻋﻦ اﻟﻌﻤﻼق اﻟﺠﻠﻴﺪي ﺑﻤﻔﻬﻮم ﺟﺪﻳﺪ ﺗﻤﺎﻣًـﺎ . أﻛﺜـﺮ ﻣـﺎ ﻳﻠﻔـﺖ اﻟﻨﻈـﺮ ﰲ ﺻـﻮرة ﺗﻠﺴﻜﻮب وﻳﺐ اﻟﺠﺪﻳﺪة ﻫﻮ ا ﻨﻈﺮ اﻟﻮاﺿـﺢ ﻟﺤﻠﻘﺎت اﻟﻜﻮﻛﺐ و ﺑﻌﻀﻬﺎ ﻟﻢ ﻳﺘﻢ اﻛﺘﺸـﺎﻓﻪ ﻣﻨﺬ أن أﺻﺒﺢ ا ﺴﺒﺎر ﺟﺮ ﺎ ﻓﻮﻳ ٢ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ أول ﻣﺮﻛﺒـﺔ ﻓﻀـﺎﺋﻴﺔ ﺗﺮﺻـﺪ ﻧﺒﺘـﻮن أﺛﻨـﺎء ﺗﺤﻠﻴﻘﻪ ﰲ ﻋﺎم ١٩٨٩ ﺑﺎﻹﺿﺎﻓﺔ إﱃ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﺤﻠﻘﺎت اﻟﺴﺎﻃﻌﺔ واﻟﻀﻴﻘﺔ، ﺗُﻈﻬﺮ اﻟ ﺼﻮرة ﺑﻮﺿﻮح أﺣﺰﻣﺔ اﻟﻐﺒﺎر اﻟﺨﺎﻓﺘﺔ ﻟﻨﺒﺘﻮن . " ﻟﻘﺪ ﻣﺮت ﺛﻼﺛﺔ ﻋﻘﻮد ﻣﻨﺬ أن رأﻳﻨﺎ آﺧﺮ ﻣﺮة ﺗﻠﻚ اﻷﺣﺰﻣﺔ اﻟﺨﺎﻓﺘﺔ وا ﻐﱪ ة وﻫﺬه ﻫﻲ ا ﺮة اﻷوﱃ اﻟﺘﻲ ﻧﺮاﻫﺎ ﰲ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤـﺮاء " ﻛﻤﺎ ﺗﻘﻮل ﻫﺎﻳـﺪي ﻫﺎﻣﻴـﻞ ﺧﺒـ ة ﰲ ﻧﻈـﺎم ﻧﺒﺘﻮن وﻋﺎ ﺔ ﻣﺘﻌﺪدة اﻟﺘﺨﺼﺼﺎت ﻟﺘﻠﺴﻜﻮب . وﻳﺐ ﺗﺴﻤﺢ ﺟﻮدة اﻟ ﻫـﺬه ﺼـﻮرة ﺷـﺪﻳﺪة اﻟﺜﺒـﺎت واﻟﺪﻗـﺔ ﺑﺎﻛﺘﺸـﺎف ﻫـﺬه اﻟﺤﻠﻘـﺎت اﻟﺨﺎﻓﺘﺔ ﺟﺪًا ﺑﺎﻟﻘﺮب ﻣﻦ . ﻧﺒﺘﻮن ﻟﻘـﺪ أذﻫـﻞ ﻫﺬا اﻟﻜﻮﻛﺐ اﻟﺒﺎﺣﺜ ﻣﻨﺬ اﻛﺘﺸﺎﻓﻪ ﰲ ﻋـﺎم ١٨٤٦ . ﻳﺒﻌﺪ ﻧﺒﺘـﻮن ٣٠ ﻋـ ﻣـﺮة ﻦ اﻟﺸـﻤﺲ ﺑ ﻣﻘﺎرﻧﺔ ﺎﻷرض وﻳﺪور ﰲ ا ﻨﻄﻘـﺔ ا ﻈﻠﻤـﺔ اﻟﺒﻌﻴﺪة ﻣﻦ اﻟﻨﻈﺎم اﻟﺸﻤﴘ اﻟﺨﺎرﺟﻲ وﻋـﲆ ﺗﻠﻚ ا ﺴﺎﻓﺔ اﻟﺸﺎﺳﻌﺔ ﺗﻜﻮن اﻟﺸﻤﺲﺻﻐ ة ﺟﺪًا وﺧﺎﻓﺘﺔ ﻟﺪرﺟﺔ ن أ وﻗﺖ اﻟﻈﻬﺮ ﰲ ﻧﺒﺘﻮن ﻳﺸــﺒﻪ اﻟﺸــﻔﻖ اﻟﺨﺎﻓــﺖ ﻋــﲆ اﻷرض . ـــــــــــــــــ ﺗ ﻜﺸــــﻒ ﻫــــﺬﻩ اﻟﺼــــﻮرة ﺑﻮاﺳــــﻄﺔ ــــﺔ ــــﺎﻣ ا اﻷﺷــــﻌﺔ ﺗﺤــــﺖ اﻟـــــ ﻤﺮاء اﻟﻘﺮ (NIRCam) ، ﻋــــﻦ ﻣ ﻤﻮﻋــــﺔ ﺻــــﻐ ة ﻣــــﻦ ﻣﺌــــﺎت اﻟﻤﺠﺮات ﻣﺘﻔﺎوﺗﺔ اﻟ ـ ﺤ ﻢ واﻟﺸ ﻞ ﺟﻨ ًﺎ إﻟﻰﺟﻨﺐ ﻣﻊ ﻧﻈـﺎم ﻮﻛـﺐ ﻧ ﺘـﻮن . ﻋﻨـﺪ ﻣﻘﺎر ـﺔ ﻧ ﺘـﻮن ﻣـﻊ اﻷرض ﻓ ﻬـﻮ ﻮﻛـﺐ ﻛﺒـ . ـﻢ إذا ﺎﻧـﺖ اﻷرضﺑﺤ ـﺔ ـﺔ ﻣﻌﺪﻧ ﻗﻄﻌــﺔ ﻧﻘﺪ ـﻢ ﻛــﺮة ا ـﺎن ﻧ ﺘـﻮن ﺑﺤ ﻟ ـﺪو ﻧ ﺘـﻮن ﺻــﻐ ًا ﻧﺴـﺒ ًﺎ ﻓـﻲﻣﺠـﺎل ﻟﺴـﻠﺔ وﻣـﻊ ذﻟــﻚ ﻳ اﻟﺮؤ ﺔ اﻟﻮاﺳﻊ ﻟﻠ ﻮن اﻟﺸﺎﺳﻊ . ﻳﻮﺟﺪ ﺎﺗﺠﺎﻩ اﻟ ـ ﺠﺰء اﻟﺴﻔﻠﻲ اﻷ ﺴﺮﻣﻦ ﻫﺬﻩ اﻟﺼﻮرة ﻣﺠﺮة ﺣﻠﺰوﻧ ﺔ ﺿﻠﻌ ﺔ ﻘﻮل اﻟﻌﻠﻤﺎء ـﺎرﺳـﻨﺔ ﺿـﻮﺋ ﺔ ـﻮن ﻋﻠـﻰ ﻌـﺪ ﺣـﻮاﻟﻲﻣﻠ ـﺘﻢ اﺳﺘﻜﺸـﺎﻓﻬﺎ ﺎﻟﺘﻔﺼـﻴﻞ ﻣـﻦ ﻗﺒـﻞ ﻗـﺪ ﺗ ﻟﻢ إن ﻫﺬﻩ اﻟﻤﺠﺮة ﺎﻟﺬات اﻟ دة ﻋـﺎ . ﻳﻣﺎ ﻋﻠﻰ ﻬ ﻤﻦ اﻟﻤﺠﺮات اﻟ ـ ﺗﻈﻬﺮ زرﻗﺎء ﻓﻲﻫﺬﻩ اﻷﻃﻮال اﻟﻤﻮﺟ ﺔ ﺤﻠﺰوﻧ ﺔ ﻣﺜﻞ ﻫﺬﻩ اﻟﻨﺠﻮم اﻟﺸﺎ ﺔ اﻟ . ُﻈﻬﺮ ﻧﻮﻓﻤ دﻳﺴﻤ 2022