Free Astronomy Magazine September-October 2023 ARABIC VERSION

Hubble sees boulders escaping from asteroid Dimorphos by NASA/ESA Bethany Downer stronomers using the NASA/ ESA Hubble Space Telescope’s extraordinary sensitivity have discovered a swarm of boulders that were possibly shaken off the aster- oid Dimorphos when NASA deliber- ately slammed the half-tonne DART impactor spacecraft into Dimorphos at approximately 22,500 kilometres per hour. DART intentionally im- pacted Dimorphos on 26 September 2022, slightly changing the trajec- tory of its orbit around the larger asteroid Didymos. The 37 ejected boulders range in size from 1 metre to 6.7 metres across, based on Hubble photome- try. They are drifting away from the asteroid at around one kilometre per hour. The total mass in these de- tected boulders is about 0.1% the mass of Dimorphos. The boulders are some of the faintest objects ever imaged in the Solar System. This opens up a new dimension for studying the aftermath of the DART experiment using the European Space Agency’s upcoming Hera mis- sion, which is due to launch in 2024. The spacecraft will perform a de- ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 20 " ﻫﺎﺑﻞ " ﻳﺮﺻﺪ ﺻﺨﻮراً ﻛﺒ ة ﺖﻓﻠﺘ أ ﻣﻦ اﻟ ﻮ ﻜﺐ د ﻤﻮرﻓﻮس : ﻘﻠﻢ ﺑ ﺜﺎﻧﻲ داوﻧﺮ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻻوروﺑ ﺔ - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 3 اﻛﺘﺸــ ﻒـ ﻋﻠﻤ ــﺎء اﻟﻔﻠ ــﻚ ﺑﺎﺳــﺘﺨﺪام اﻟﺤ اﻟ ﺴﺎﺳﻴﺔ ﻐ ﻋﺎدﻳـﺔ ﻟﺘﻠﺴـﻜﻮب ﻫﺎﺑـﻞ اﻟﻔﻀﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟﻨﺎﺳـﺎ ووﻛﺎﻟـﺔ اﻟﻔﻀـﺎء اﻷوروﺑﻴﺔ ﺎً ﺑـﴎ ﻣـﻦ اﻟﺼـﺨﻮر اﻟﺘـﻲ ﻣـﻦ ا ﺤﺘﻤﻞ أن ﺗﻜﻮن ﻗﺪ أﻓﻠﺘﺖ ﻣـﻦ اﻟﻜﻮﻳ ﻜـﺐ دﻳﻤﻮرﻓﻮس ﻋﻨﺪﻣﺎ ﻗﺎﻣﺖ وﻛﺎﻟﺔ ﻧﺎﺳﺎ ﺑﺠﻌﻞ ا ﺮﻛﺒﺔ اﻟﻔﻀﺎﺋﻴﺔ ( دارت) اﻟﺘﻲ ﻳﺒﻠﻎ وزﻧﻬـﺎ ﻧﺼﻒ ﻃـﻦ ﺗﺼـﻄﺪم ﻋﻤـﺪاً ﺑـ ﺪﻳﻤﻮرﻓﻮس ـﺑ ﴪﻋﺔ 22500 ﻛﻴﻠﻮﻣﱰ ﰲ اﻟﺴﺎﻋﺔ ﺗﻘﺮﻳﺒًﺎ . ـﺑ ﴪﻋﺔ 22500 ﺑ ﻛﻴﻠﻮﻣﱰ ﺎﻟﺴﺎﻋﺔ ﺗﻘﺮ ﺎً ﻳﺒـ ﰲ 26 ﺳــﺒﺘﻤﱪ 2022 ﻣﻤــﺎ أ دى إﱃ ﺗﻐﻴ ـ ﻃﻔﻴـﻒ ﰲ ﻣﺴـﺎر ﻣـﺪار اﻟﻜﻮﻳﻜـﺐ ﺣــﻮل اﻟﻜﻮﻳﻜﺐ اﻷﻛﱪ ﺣﺠﻤ ﺎً ا ﺴﻤﻰ دﻳﻤﻮرﻓﻮس . ﻳﱰاوح ﺣﺠﻢ اﻟﺼﺨﻮر ا ﻘﺬوﻓﺔ اﻟـ 37 ﻣﻦ ﻣﱰ واﺣﺪ إﱃ 6.7 اً ﻣﱰ ﺑﻨﺎءً ﻋﲆ اﻟ ﻘﻴﺎﺳـ ﺎت ﺑﻮاﺳﻄﺔ ﺗﻠﺴـﻜﻮب ﻫﺎﺑـﻞ اﻟﻀـﻮﺋﻲ وﻫـﻲ ﺗﻨﺠﺮف ﺑﻌﻴﺪ اً ﻋﻦ اﻟﻜﻮﻳﻜﺐ ﺑ ـ ﴪﻋﺔ ﺗﺒﻠـﻎ ٠.١ % ﻣﻦ ﻛﺘﻠﺔ اﻟﺪﻳﻤﻮرﻓﻮس . ﺣﻮاﱄ ﻛﻴﻠﻮﻣﱰ واﺣﺪ ﺑ ﺎﻟﺴﺎﻋﺔ . ﺗﺒﻠﻎ اﻟﻜﺘﻠـﺔ اﻹﺟﻤﺎﻟﻴﺔ ﻟﻬﺬه اﻟﺼﺨﻮر ا ﻜﺘﺸـﻔﺔ ﺣـﻮاﱄ 0.1 % ﻣــﻦ ﻛﺘﻠــﺔ اﻟــﺪﻳﻤﻮرﻓﻮس . ﺗﻌﺘــﱪ اﻟﺼﺨﻮر ﻣـﻦ أﺿـﻌﻒ اﻷﺟﺴـﺎم اﻟﺘـﻲ ﺗـﻢ ﺗﺼﻮﻳﺮﻫﺎ ﻋﲆ اﻹﻃﻼق ﰲ اﻟﻨﻈﺎم اﻟﺸﻤ ﴘـ وﻫﺬا ﻳﻔﺘﺢ ﺑﻌﺪ اً اً ﺟﺪﻳﺪ ﻟﺪراﺳﺔ آﺛﺎر ﺗﺠﺮﺑـﺔ ( دارت) ﺑﺎﺳﺘﺨﺪام ﻣﻬﻤﺔ ( ﻫـ ا ) اﻟﺠﺪﻳـﺪة ﻟﻮﻛﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑﻴﺔ واﻟﺘﻲ ﻣﻦ ا ﻘـﺮر إﻃﻼﻗﻬﺎ ﰲ ﻋﺎم 2024 . وﺳﺘﺠﺮي ا ﺮﻛﺒﺔ إﻛﺘﺸﻒ