Free Astronomy Magazine July-August 2024 ARABIC VERSION

ing that none of the obser- vations we’ve been getting have robustly solved these mys- teries. I am thrilled that we’re finally get- ting some answers!” Un- like the atmospheres of gas giant planets, which are relatively easy to spot (the first was detected by NASA’s Hubble Space Telescope more than two decades ago), thinner and denser at- mospheres surrounding rocky plan- ets have remained elusive. Previous studies of 55 Cancri e us- ing data from NASA’s now-retired Spitzer Space Telescope suggested the presence of a substantial atmos- phere rich in volatiles (molecules that occur in gas form on Earth) like oxygen, nitrogen, and carbon diox- ide. But researchers could not rule out another possibility: that the planet is bare, save for a tenuous shroud of vaporized rock, rich in elements like silicon, iron, alu- minum, and calcium. “The planet is so hot that some of the molten rock should evaporate,” explained Hu. To distinguish between the two possibilities, the team used Webb’s N I R C a m ( Near- Infrared Camera) and MIRI (Mid-In- frared Instrument) to measure 4- to 12-micron infrared light coming from the planet. Although Webb cannot capture a direct image of 55 Cancri e, it can measure subtle changes in light from the system as the planet orbits the star. JULY-AUGUST 2024 " ﻟﻘﺪ ﻛﺎن ﻣﻦ ا ﺤﺒﻂ ﺎً ﺣﻘ أن أﻳ ﻣﻦ ﺎً اﻷرﺻــﺎد ﺘﻲـاﻟ ﺗﻠﻘﻴﻨﺎﻫﺎ ﻟﻢ ﺗﻨ ﺠﺢـ ﺎز ـﻐـ ﺬه اﻷﻟ ـﻞ ﻫـﰲ ﺣ ﺑﺸﻜﻞ ﻗﻮي . أﺷﻌﺮ ﺑﺴﻌﺎدة ﻨﺎ ﺣﺼ ـ ﻏﺎﻣﺮة ﻷﻧ ﻠﻨﺎ أﺧ ـ اً ـ ﻋﲆ ﺑﻌﺾ اﻹﺟﺎﺑﺎت ! ﻋﲆ ﻋﻜﺲ اﻷﻏﻠﻔﺔ اﻟﺠﻮﻳﺔ ﻟﻠ ﻮاﻛﺐ اﻟﻐ ﻜـ ﺎزﻳﺔ ـ اﻟﻌﻤ ﺘﻲ ﻳﺴ ـاﻟ ﻼﻗﺔ ـ ﻬﺎـ ﺘﺸﺎﻓ ـ ﻬﻞ اﻛ ـ ﻧﺴــﺒﻴ ) ﺎً ﺗــﻢ اﻛﺘﺸــﺎف اﻷوﱃ ﺑﻮاﺳــﻄﺔ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨ ﺎﺳﺎ ﻣﻨـﺬ أﻛﺜﺮ ﻣﻦ ﻋﻘﺪﻳﻦ ﻣﻦ اﻟﺰﻣﻦ ( ﻇﻠﺖ اﻷﻏﻠﻔـﺔ اﻟﺠﻮﻳــﺔ اﻷرق واﻷﻛﺜــﺮ ﻛﺜﺎﻓــﺔ ا ﺤﻴﻄــﺔ ﺑﺎﻟﻜﻮاﻛﺐ اﻟﺼﺨﺮﻳﺔ ﺑﻌﻴﺪة ا ﻨﺎل . اﻗﱰﺣـﺖ اﻟﺪراﺳـﺎت اﻟﺴـﺎﺑﻘﺔ اﻟﺘ ـﻲ أﺟﺮﻳ ـﺖ ﻋ ـ ﲆ اﻟﻜﻮﻛــﺐ )55 ﻛــﺎﻧﻜﺮي إي ( ﺑﺎﺳــﺘﺨﺪام ﺑﻴﺎﻧﺎت ﺗﻠﺴﻜﻮب ﺳﺒﻴﺘﺰر اﻟﻔﻀﺎ ﺋﻲ ا ﺘﻘﺎﻋﺪ ﺣﺎﻟﻴًﺎ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ وﺟﻮد ﻏﻼف ﺟﻮي ﻛﺒـ ﻏﻨﻲ ﺑﺎ ﻮاد ا ﺘﻄﺎﻳﺮة ) اﻟﺠﺰﻳﺌﺎت اﻟﺘﻲ ﺗﻮﺟﺪ ﰲ ﺷﻜﻞ ﻏﺎز ﻋﲆ اﻷرض ( ﻣﺜـﻞ اﻷﻛﺴـﺠ ـــ واﻟﻨﻴﱰوﺟ وﺛﺎﻧﻲ أﻛﺴﻴﺪ اﻟﻜﺮﺑﻮن ﻟﻜﻦ اﻟﺒﺎﺣﺜ ﻟﻢ ﻳﺘﻤﻜﻨﻮا ﻣﻦ اﺳﺘ ﺒﻌﺎد اﺣﺘﻤـﺎل آﺧـﺮ أن : اﻟﻜﻮﻛﺐ ﺧﺎلٍ ﺑﺎﺳـﺘ ﺜﻨﺎء ﻏﻄـﺎء ﻫـﺶ ﻣـﻦ اﻟﺼـﺨﻮر ا ﺘﺒﺨـﺮة اﻟﻐﻨﻴـﺔ ﺑﻌﻨـﺎﴏﻣﺜـﻞ اﻟﺴـــﻴﻠﻴﻜﻮن واﻟﺤﺪﻳـــﺪ واﻷﻟﻮﻣﻨﻴـــﻮم واﻟﻜﺎﻟﺴﻴﻮم . أوﺿﺢ " أن (ﻫﻮ) اﻟﻜﻮﻛﺐ ﺣﺎر اً ﺟﺪ ﻟﺪرﺟﺔ أن ﺑﻌـﺾ اﻟﺼـﺨﻮر ا ﻨﺼـﻬﺮة ــــ ﻳﺠﺐ أن ﺗﺘﺒﺨ ـﺮ ." ﻟﻠﺘﻤﻴﻴ ـﺰ ﺑــ اﻻﺣﺘﻤــﺎﻟ اﺳــﺘﺨﺪم اﻟﻔﺮﻳــﻖ ﻛــﺎﻣ ا ﻧ ﻛﺎم ) ( ﻟﺘﻠﺴﻜﻮب وﻳﺐ ) ﻛـﺎﻣ ا اﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒـﺔ ( وﻛـﺎﻣ ا ( ﻣـ ي ) ) أداة اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء ا ﺘﻮﺳـﻄﺔ ( ﻟﻘﻴﺎس دﻗﻴﻖ ﻟ ﻀﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤـﺮاء ﻣﻦ 4 إﱃ 12 ﻣﻴﻜﺮون اﻟﻘﺎدم ﻣﻦ اﻟﻜﻮﻛـﺐ . ــ ﻳﻮﺿﺢ ﻫﺬا اﻟ ﺮﺳﻢ اﻟﺘﺨ ﻠﻲ اﻟﺸـ ﻞ اﻟﻤﺤﺘﻤـﻞ ﻟ ﻠ ﻮﻛﺐ اﻟﻨ ﻤﻲ )55 ﺎﻧﻜﺮي إي ( . [NASA, ESA, CSA, Ralf Crawford (STScI)] - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 4