I-atmosfera ngumaleko werhasi ejikeleze indawo esesibhakabhakeni, efana noMhlaba, otsalwa ngumxhuzulane. Ikhusela kwimitha ye-ultraviolet yelanga, ilawula ubushushu kwaye ithintele ukungena kweemeteorites. Ukuba ummandla ojikeleze umhlaba ubungenazo iimpawu onazo ngoku, umhlaba ubungenakukwazi ukuxhasa ubomi. Nangona kunjalo, abantu abaninzi bayazibuza ukuba yintoni na ukwakheka kwendawo.
Ngenxa yesi sizathu, siza kunikela eli nqaku ukukuxelela malunga nokubunjwa kwe-atmosfera, xa yadalwa kunye nendlela eyakhiwe ngayo.
Ukuyilwa komoya
I-atmosfera ngumaleko wegesi ojikeleze isijikelezi-langa sethu, kwaye ubukho bawo bubangelwa ngumtsalane womxhuzulane woMhlaba. Yaqala ukumila kunye nemvelaphi yoMhlaba malunga ne-4.600 yezigidigidi zeminyaka eyadlulayo. Ngeminyaka yokuqala eyi-500 yezigidi, iatmosfera yaqala ukuvela; Njengoko ubuphakathi besijikelezi-langa sethu esiselula sasiqhubeka siqhelana, sasixinene ngokungaqhelekanga ngumphunga neegesi ezikhutshwayo. Iigesi eziqulunqayo zingaba yi-hydrogen (H2), umphunga wamanzi, i-methane (CH4), i-helium (He) kunye ne-carbon oxides. Leyo yimeko yamandulo kuba umoya ojikeleze umhlaba wawungenakubakho kwiminyaka eyi-200 yezigidi eyadlulayo. Umhlaba wawuseshushu kakhulu ngelo xesha, nto leyo eyayikhuthaza ukukhutshwa kweegesi ezilula.
Umxhuzulane womhlaba ungaphantsi kancinane kunokuba unjalo namhlanje, nto leyo ethintela uMhlaba ekugcineni iimolekyuli kwindawo ekuwo; imagnetosphere nangoku ayikabunjwa kwaye umoya welanga uvuthuza ngokuthe ngqo phezu komhlaba. Konke oku kwabangela ukuba umoya wamandulo unyamalale esibhakabhakeni.
Iplanethi yethu, ngenxa yobushushu bayo, ubungakanani kunye nobunzima obuphakathi, ayikwazi ukugcina iigesi ezilula kakhulu njengehydrogen kunye nehelium, ezibalekela emajukujukwini kwaye zirhuqwe ngumoya welanga. Nobunzima bomhlaba obukhoyo, akunakwenzeka ukugcina iigesi ezinjengehelium kunye nehydrogen, ngokungafaniyo neeplanethi ezinkulu ezifana neJupiter kunye neSaturn, ezinomoya otyebileyo wegesi. Amatye abumba iplanethi yethu ahlala ekhupha iigesi ezintsha kunye nomphunga wamanzi ixesha elide kude kube malunga ne-4.000 yezigidigidi zeminyaka eyadlulayo, xa i-atmosfera yaqala ukubunjwa ziimolekyuli zekhabhoni. carbon dioxide (CO2), carbon monoxide (CO), amanzi (H2O), initrogen (N2), kunye nehydrogen (H).
Umvelaphi
Ubukho bezi khompawundi kunye nokuhla kobushushu boMhlaba obungaphantsi kwe-100°C kukhokelele kuphuhliso lwe-hydrosphere ethi. yaqala ukwenza malunga ne-4 yezigidigidi kwiminyaka eyadlulayo.
Iminyaka yokuxinana komphunga wamanzi ibe nesiphumo sokwenziwa komthamo omkhulu wamanzi ovumela inkqubo yokubekwa. Ubukho bamanzi buthanda ukuchithwa kweegesi ezifana ne-sulphur dioxide, i-hydrochloric acid okanye i-carbon dioxide, ukwakheka kwee-asidi kunye nokusabela kwazo kunye ne-lithosphere, ekhokelela ekunciphiseni umoya. Iigesi ezifana ne-methane kunye ne-ammonia. Ngeminyaka yoo-1950, umphandi waseMelika uStanley Miller wayila umfuniselo wakudala ukubonisa ukuba ngesenzo samandla athile angaphandle. wasebenzisa ukukhutshwa kombane ukufumana umxube wee-amino acids kuloo ndawo.
Ngokwenjenjalo, uceba ukuphinda adale iimeko ezicocekileyo ezisesibhakabhakeni ezinokuvelisa imvelaphi yobomi. Kuyavunywa ngokubanzi ukuba kukho ubuncinci beemeko ezintathu zobomi njengoko sibuqonda: umoya ozinzile otyebile kwizinto ezifana neoksijini kunye nehydrogen, umthombo osisigxina wamandla angaphandle, kunye namanzi alulwelo. Njengoko sele sibonile, iimeko zobomi ziphantse zamiselwa. Nangona kunjalo, ngaphandle kweoksijini yasimahla, ubomi ngokwabo bunokuba zizigidi zeminyaka kude. Ukwakheka kwamatye okuqulathe izixa-mkhondo zezinto ezifana ne-uranium kunye nentsimbi bubungqina bomoya we-anaerobic. Ngoko ke, ezi zinto azifumaneki kumatye avela kwi-Precambrian ephakathi okanye ubuncinane kwiminyaka eyi-3 yeebhiliyoni kamva.
Ukubaluleka kweoksijini
Kwizinto eziphilayo ezifana nathi, eyona nkqubo ibalulekileyo ye-atmospheri kukwakheka kweoksijini. Iinkqubo zemichiza ezithe ngqo okanye iinkqubo zejoloji ezifana nokusebenza kwentaba-mlilo azivelisi ioksijini. Ngoko ke, kukholelwa ukuba ukubunjwa kwe i-hydrosphere, i-atmosfera ezinzileyo kunye namandla elanga ziimeko ukwenzela ukwakhiwa kweeprotheni elwandle kunye nenkqubo ye-amino acid condensation kunye ne-synthesis. ye-nucleic acids ethwele ikhowudi yezofuzo, kwi-1.500 yezigidi zeminyaka Kamva, izinto eziphilayo ze-anaerobic ezingabonakaliyo zivela elwandle. Kwiminyaka nje eyibhiliyoni eyadlulayo, izinto eziphilayo zasemanzini ezibizwa ngokuba yicyanobacteria zaqalisa ukusebenzisa amandla elanga ukuqhekeza iimolekyuli.
Amanzi (H2O) kunye ne-carbon dioxide (CO2) adityaniswa kwakhona kwi-organic compounds kunye ne-oxygen yamahhala (O2), oko kukuthi, xa i-chemical bond phakathi kwe-hydrogen kunye ne-oksijini yaphukile, le yokugqibela ikhutshwa kwimo engqongileyo iphuma kwi-oksijini. iphotosynthesis idibanisa ne organic carbon ukwenza iimolekyuli zeCO2. Inkqubo yokuguqula amandla elanga abe yioksijini yasimahla ngokwahlukana kwemolekyuli ibizwa ngokuba yiphotosynthesis kwaye yenzeka kwizityalo kuphela, nangona ilinyathelo elikhulu elisingise kwiatmosfera yoMhlaba esinayo namhlanje. Le yintlekele enkulu kwizinto eziphilayo ze-anaerobic, kuba ukuba i-oxygen emoyeni iyanda, i-CO2 iyancipha.
Ukwenziwa kweatmosfera kunye neegesi
Ngelo xesha, ezinye iimolekyuli zeoksijini ezisemoyeni zifunxa amandla kwimitha ye<em>ultraviolet ekhutshwa lilanga zize zahlukane zenze iiathom zeoksijini. Ezi athom zidibana neoksijini eseleyo zenze iimolekyuli ze-ozone ( O3 ), ezifunxa ukukhanya kwe<em>ultraviolet elangeni. Kwiminyaka eyi-4 yezigidigidi, isixa se-ozone sasinganelanga ukuvimba ukungena kokukhanya kwe-ultraviolet, oku akuyi kuvumela ukuba ubomi bube khona ngaphandle kweelwandle. Malunga nezigidi ezingama-600 kwiminyaka eyadlulayo, ngenxa yezinto eziphila elwandle, iatmosfera yoMhlaba yafikelela kuyo amanqanaba e-ozone aphezulu ngokwaneleyo ukuba afunxe ukukhanya okuyingozi kwe-ultraviolet, nto leyo eyakhokelela ekuveleni kobomi kumazwekazi. Ngeli xesha, izinga le-oksijeni li malunga ne-10% yexabiso langoku. Yiyo loo nto, ngaphambi koku, ubomi babuphelele elwandle. Nangona kunjalo, ubukho be-ozone bubangela ukuba izinto eziphilayo zaselwandle zifudukele emhlabeni.
Ukusebenzisana okuqhubekayo kunye neziganeko ezahlukeneyo zomhlaba kwaqhubeka kwenzeka kwi-atmosfera de kwafikelela kwisakhiwo esikhoyo ngoku iipesenti ze-99 ze-hydrogen, i-oksijini kunye ne-argon. Okwangoku, i-atmosfera ayisebenzi nje kuphela ukukhusela izinto ezahlukeneyo ezibonakalayo ezenzeka esikhaleni, kodwa ikwasebenza njengomlawuli ongaqhelekanga wenkqubo ye-thermodynamic, imichiza kunye nebhayoloji ngokwendalo kunye nendalo. Iziganeko zomhlaba, ngaphandle apho ubomi abuyi kuba njengoko siyazi. Oko kudibana rhoqo kwamaqondo obushushu olwandle, ukukhuselwa kwe-ozone kwimitha yelanga eyingozi, nemozulu ezolileyo ngokwentelekiso kwabangela ukuba ubomi buqhubeke buguquka.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga nokubunjwa kwe-atmosphere kunye nendlela eyenziwa ngayo.