Free Astronomy Magazine March-April 2026 ARABIC VERSION

A thick atmosphere around broiling lava world byNASA/ESA/CSA NASAWebbMissionTeam esearchersusingNASA’sJames WebbSpaceTelescopehave detectedthestrongestevi-dence yet for an atmosphere on a rocky planet outside our solar sys-tem. Observations of the ultra-hot super-Earth TOI-561 b suggest that theexoplanetissurroundedbya thickblanketofgasesaboveaglobal magmaocean.Theresultshelpex- plaintheplanet’sunusuallylowden- sityandchallengetheprevailing wisdomthatrelativelysmallplanets soclosetotheirstarsarenotableto sustainatmospheres.Witharadius roughly1.4timesEarth’s,andanor- bitalperiodlessthan11hours,TOI- 561bfallsintoarareclassofobjects knownasultra-shortperiodexoplan- ets. Although its host star is only slightlysmallerandcoolerthanthe Sun,TOI-561borbitssoclosetothe star — less than one million miles (one-fortieththedistancebetween MercuryandtheSun)—thatitmust betidallylocked,withthetempera- tureofitspermanentdaysidefarex- ceedingthemeltingtemperatureof typicalrock. “Whatreallysetsthis planetapartisitsanomalouslylow density,” said Johanna Teske, staff scientist at Carnegie Science Earth and Planets Laboratory and lead au- thor on a paper published in The As- trophysicalJournalLetters . “It’snot asuper-puff,butitislessdensethan you would expect if it had an Earth- like composition.” One explanation theteamconsideredfortheplanet’s low density was that it could have a relativelysmallironcoreandaman-tle made of rock that is not as dense asrockwithinEarth.Teskenotesthat this could make sense: “TOI-561 b is distinctamongultra-shortperiod MARCH-APRIL2026 R رﺻﺪ ﻏﻼفﺟﻮيﻛﺜ ﻒﺣﻮل ﻮﻛﺐﻣﺴﺘﻌﺮﺳﺎﺧﻦ : ﻘﻠﻢ ﻓﺮﻖ ﻣﻬﻤﺔ ﺗﻠﺴ ﻮب و ﺐ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ إ ﺴﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ اﻛﺘﺸـﻒ ﺑ ـﺎﺣﺜﻮن ﺑﺎﺳـﺘﺨﺪام ﺗﻠﺴـﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ أﻗـﻮى دﻟﻴﻞ ﺣﺘﻰ اﻵن ﻋﲆ وﺟﻮد ﻏﻼف ﺟﻮي ﻋـﲆ ﻛﻮﻛﺐ ﺻﺨﺮي ﺧﺎرج ﻧﻈﺎﻣﻨـﺎ اﻟـ . ﺸﻤﴘـ ﺗﺸ اﻷرﺻﺎد اﻟﺘﻲ أﺟﺮﻳـﺖ ﻋـﲆ اﻟﻜﻮﻛـﺐ اﻟﻌﻤﻼق ﺷﺪﻳﺪ اﻟﺤـﺮارة TOI-561 b إﱃ أن ﻫﺬا اﻟﻜﻮﻛﺐ ﻣﺤـﺎط ﺑﻐﻄـﺎء ﺳـﻤﻴﻚ ﻣـﻦ اﻟﻐﺎزات ﻓﻮق ﻣﺤﻴﻂ ﻛﺮوي ﻣـﻦ اﻟﺼـﻬﺎرة وﺗﺴﺎﻋﺪ ﻫـﺬه اﻟﻨﺘـﺎﺋﺞ ﰲ ﺗﻔﺴـ اﻟﻜﺜﺎﻓـﺔ ا ﻨﺨﻔﻀـﺔ ﺑﺸـﻜﻞ ﻏـ ﻋـﺎدي ﻟﻠﻜﻮﻛـﺐ وﺗﺘﺤﺪى اﻻﻋﺘﻘـﺎد اﻟﺴـﺎﺋﺪ ﺑـﺄن اﻟﻜﻮا ﻛـﺐ اﻟﺼﻐ ة ﻧﺴﺒﻴًﺎ اﻟﻘﺮﻳﺒﺔ ﺟﺪًا ﻣـﻦ ﻧﺠﻮﻣﻬـﺎ ﻏ ﻗﺎدرة ﻋﲆ اﻟﺤﻔﺎظ ﻋﲆ ﻏـﻼف ﺟـﻮي . ﻳﺒﻠﻎ ﻧﺼﻒ ﻗﻄﺮه ﺣﻮاﱄ 1.4 ﺿﻌﻒ ﻧﺼـﻒ ﻗﻄﺮ اﻷرض ﻳو ﺪور دورة ﺣﻮل اﻟﺸـﻤﺲ ﰲ ـــ ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 36 أﻗـﻞ ﻣـﻦ 11 . ﺳـﺎﻋﺔ ﻳﻨـﺪرج TOI-561 b ﺿﻤﻦ ﻓﺌﺔ ﻧﺎدرة ﻣﻦ اﻷﺟ ﺮام ا ﻌﺮوﻓﺔ ﺑﺎﺳﻢ اﻟﻜﻮاﻛﺐ اﻟﺨﺎرﺟﻴﺔ ذات اﻟﺪورات اﻟﻘﺼـ ة . اً ﺟﺪ ﻋﲆ اﻟﺮﻏﻢ ﻣﻦ أن ﻧﺠﻤﻪ أﺻـﻐﺮ ﻗﻠـﻴﻼً وأﺑﺮد ﻣﻦ اﻟﺸﻤﺲ ﻳـﺪور TOI-561 b ﻋـﲆ ﻣﺴﺎﻓﺔ ﻗﺮﻳﺒﺔ ﺟ اً ﺪ ﻣـﻦ اﻟـﻨﺠﻢ - أﻗـﻞ ﻣـﻦ ﻣﻠﻴﻮن ﻣﻴﻞ ) واﺣﺪ ﻣﻦ أرﺑﻌ ﻣﻦ ا ﺴـﺎﻓﺔ ﺑ ﻋﻄﺎرد واﻟﺸﻤﺲ ( ﻟﺪرﺟ ﺔ أﻧﻪ ﻳﺠـﺐ أن ﻳﻜﻮن ﻣﻘﻴـﺪاً ﻣـﺪﻳﺎً ﺣﻴـﺚ ﺗﺘﺠـﺎوز درﺟـﺔ ﺣﺮارة ﺟﺎﻧﺒﻪ اﻟﻨﻬﺎري اﻟﺪاﺋﻢ درﺟﺔ اﻧﺼﻬﺎر اﻟﺼﺨﻮر اﻟ ﻨﻤﻮذﺟﻴﺔ ﺑﻜﺜـ . ﻗﺎﻟـﺖ ﺟﻮاﻧـﺎ ﺗﻴﺴــﻜﻲ اﻟﻌﺎ ـﺔ ﰲ ﻣﺨﺘ ـﱪ ﻋﻠ ـﻮم اﻷرض واﻟﻜﻮاﻛﺐ ﰲ ﻣﺆﺳﺴﺔ ﻛـﺎرﻧﻴﺠﻲ وا ﺆﻟﻔـﺔ اﻟﺮﺋﻴﺴﻴﺔ ﻟﻮرﻗﺔ ﺑﺤﺜﻴـﺔ ﻧـ ـ ﴩت ﰲ ﻣﺠﻠـﺔ رﺳﺎﺋﻞ اﻟﻔﻴﺰﻳﺎء اﻟ ﻔﻠﻜﻴﺔ اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﺮﻗﻤﻴﺔ : ــــــــــــــــــــــ ــــــــــــــ " ﻣﺎ ﻳﻤﻴﺰ ﻫﺬا اﻟﻜﻮﻛـﺐ ﺣﻘـ ﺎ ﻫـﻮ ﻛﺜ ﺎﻓﺘـﻪ ا ﻨﺨﻔﻀﺔ ﺑﺸﻜﻞ ﻏ ﻃﺒﻴﻌﻲ إﻧﻪ ﻟﻴﺲ ﻛﺘﻠﺔ ﻧﺠﻤﻴﺔ ﺿﺨﻤﺔ وﻟﻜﻨﻪ أﻗﻞ ﻛﺜﺎﻓﺔ ﻣﻤﺎ ﻳﺘﻮﻗﻊ ﻟﻮ ﻛﺎن ﺗﺮﻛﻴﺒﻪ ﻣﺸـﺎﺑﻬ ﺎً ﻟﱰﻛﻴـﺐ اﻷرض ." أﺣـﺪ اﻟﺘﻔﺴ ـ ات اﻟﺘ ـﻲ درﺳـﻬﺎ اﻟﻔﺮﻳ ـﻖ ﻻﻧﺨﻔﺎض ﻛﺜﺎﻓﺔ اﻟﻜﻮﻛﺐ ﻫﻮ أﻧﻪ ﻗﺪ ﻳﻜـﻮن ﻟﺪﻳﻪ ﻧﻮاة ﺣﺪﻳﺪﻳﺔ ﺻﻐ ة ﻧﺴـﺒﻴ ﺎً ووﺷـﺎح ﻣﺼﻨﻮع ﻣﻦ ﺻﺨﻮر أﻗﻞ ﻛﺜﺎﻓﺔ ﻣﻦ ﺻﺨﻮر اﻷرض . ﻳﺸ ﺗﻴﺴﻜﻲ إﱃ أن ﻫﺬا ﻗﺪ ﻳﻜـﻮن : " ﻣﻨﻄﻘﻴﺎً ﻳﺘﻤﻴﺰ اﻟﻜﻮﻛﺐ TOI-561 b ﺑـ اﻟﻜﻮاﻛﺐ ذ ات اﻟﺪورات اﻟﻘﺼ ة ﺟـﺪاً ﺑﺄﻧـﻪ ﻳﺪور ﺣﻮل ﻧﺠﻢ ﻗﺪﻳﻢ ﺟـﺪاً ) ﻋﻤـﺮه ﺿـﻌﻒ ﻋﻤﺮ اﻟﺸﻤﺲ ( ﻓﻘ ﺑﺎﻟﺤﺪﻳﺪ ﰲ ﻣﻨﻄﻘﺔ ﻣﻦ ﻣﺠﺮة درب اﻟﺘﺒﺎﻧﺔ ﺗ ﻌﺮف ﺑﺎﻟﻘﺮص اﻟﺴﻤﻴﻚ . ﻻ ﺑﺪ أﻧﻪ ﻗﺪ ﺗﺸ ﻜﻞ ﰲ ﺑﻴﺌﺔ ﻛﻴﻤﻴﺎﺋﻴﺔ ﻣﺨﺘﻠﻔﺔ ــــــــــــــــــــــ - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 6