Amagama athi "alien" nelithi "extraterrestrial" avame ukuhlotshaniswa nabalingiswa emisebenzini yezinganekwane zesayensi. Nokho, nakuba kuwukuqagela, kukhona igatsha lebhayoloji eliphenya futhi licubungule ubukhona bokuphila okungaphandle komhlaba: i-exobiology.
Kodwa kungenzeka kanjani ukutadisha izinto eziphilayo ezingafakazelwa ubukhona bazo? Yini futhi kuphi okufanele izazi ze-exobiology zibheke ukuze ziqonde uma kukhona ukuphila endaweni yonke?
Lukudweba i-equation
Ngo-1960 uFrank Drake, isazi sezinkanyezi saseMelika, wenza uphenyo lokuqala eNational Radio Astronomy Observatory, ukuzama ukuthola amasignali omsakazo avela empucukweni yangaphandle. Ngemva konyaka, uDrake wenza i-equation esasetshenziswa nanamuhla emkhakheni we-exobiology, eklanyelwe ukulinganisa inani lempucuko yangaphandle emthaleni wethu, eboniswa yincwadi. N.
I-equation kaDrake ibheka imingcele eminingana futhi yenziwe kanje:
Amanani we-Equation
Inani lokuqala lithi R *, okuyizinga lokwakheka kwezinkanyezi ku-Milky Way. Ngemva kwalokho, kufanele kucatshangelwe izinkanyezi kuphela ezixhumene nezinhlelo zamaplanethi; lezi kumele zibe nezimo ezidingekayo zokusingatha impilo, izidingo okungelula ukuzenelisa futhi zimelelwe ngazo ngokulandelana kwazo f p y n e . F l ihambisana nengxenye yamaplanethi lapho ukuphila kufanele kuthuthuke, kuyilapho fi es ingxenye yalezi lapho ukuphila okukhulayo kuhlakaniphile.
Akufanele nje kube smart, kodwa variable f cithi lezi zinhlobo zokuphila kufanele zikwazi ukuthuthukisa ubuchwepheshe obukhipha isignali yomsakazo emkhathini. Okuguquguqukayo kokugcina ngu L, isikhathi lapho amasignali okufanele athunyelwe ngaso. Njengoba kubonakala, okuguquguqukayo kuningi futhi kunzima ukusungula inani eliqondile ngalinye, ngakho-ke sikhuluma ngamathuba. Nokho, kukhona izilinganiso kanye nemiphumela, okungenani ngokombono, ukunikeza inani kokuguquguquka N bese uphendula umbuzo.
Izincazelo nezisombululo
Kusukela ekwakhiweni kokuqala kwe-Equation, ososayensi abaningi baye bazama ukuchaza kabanzi ngomphumela wayo. Kusukela ngeminyaka yawo-1960s kuze kube namuhla, amathuluzi esayensi atholakalayo okucubungula amanani ashintshile, kodwa isibalo, empeleni, kuseyindlela yokuxoxa ngendaba ngokwesayensi, kunokuba sinikeze izimpendulo eziqondile.
Izilinganiso zakamuva zithatha impucuko yangaphandle kwama-23 (i-exobiology)
Kodwa-ke kungani singakaze sibe nobufakazi bokuba khona kwayo? Lona kanye inkinga eyaziwa ngokuthi Indida kaFermi, eyathatha igama layo kusazi sefiziksi sase-Italy esahlongoza okokuqala, u-Enrico Fermi. Njengoba singekho isiqiniseko salokhu, ososayensi abasebenzelana ne-exobiology namuhla baye bazama ukugxilisa ukunaka kwabo ezidingweni okumelwe ukuba izinto eziphilayo zibe nazo ukuze zithuthuke, ngaphandle kokushiya ngaphandle izindawo ezinobutha kakhulu.
I-Exobiology: izimo zokuphila zibe khona
Uma ufuna amafomu okuphila emkhathini, kucatshangwa ukuthi atholakala kumaplanethi anezici ezifanayo kakhulu nezoMhlaba: inala yamanzi, imithombo yamandla kanye namanye ama-molecule ayisisekelo.
Ngokwezazi ze-exobiologist, lezi yizimfuneko eziyisisekelo, kodwa kumelwe sikhumbule ukuthi asinakuqiniseka ukuthi ukuphila kusekelwe kuma- molecule afanayo ngaso sonke isikhathi.
Ngokuvamile, asinaso isiqiniseko sokuthi kungaba njalo cabanga ngobukhona bempilo uma zonke izithako esivame ukuzicabangela njengezibalulekile zikhona: i-solvent enguketshezi, umthombo wamandla kanye nalokho okubizwa ngokuthi izakhi eziyisisekelo, okungukuthi, ama-molecule ayisisekelo, i-organic kanye ne-inorganic , lokho kuhlangene nokukodwa kubangela izakhiwo eziyinkimbinkimbi. Amanye amapharamitha aguquguqukayo yi-pH, izinga lokushisa, ingcindezi, usawoti kanye nemisebe. Amaplanethi anezici ezifanayo nezoMhlaba ajwayele ukubizwa ngokuthi exoplanets.
Kodwa-ke, ngenxa yezinto eziphilayo ezaziwa ngokuthi ama-extremophiles, siyazi ukuthi ukuphila kungachuma hhayi kuma-exoplanets kuphela, kodwa noma yikuphi lapho kunemibandela encane khona.
ama-exoplanets nonyaka okhanyayo
Esikubizayo Ama-Exoplanets Ziyizindikimba zasezulwini eziyingxenye yesimiso sonozungezilanga, kweyethu noma kweminye imithala. Zizungeza ilanga lazo kude okuvumela ukuba khona kwamanzi awuketshezi noma ezinye izincibilikisi, enye yezidingo ezibaluleke kakhulu ekuthuthukisweni kwempilo. Lawa maplanethi, njengoMhlaba, angaba nenqwaba yezindawo lapho izimo zamakhemikhali nezomzimba zingase zibe zinhle ukusekela ukuphila. Ngeshwa, eziningi zazo zikude ngeminyaka embalwa yokukhanya esimisweni sethu sonozungezilanga.
El unyaka wokukhanya yibanga elihanjwa ukukhanya onyakeni owodwa. Ukukhanya okuvela eLangeni kufinyelela kithi ngemizuzu eyi-8 nesigamu, kuhamba ibanga elingamakhilomitha ayizigidi ezingu-150. Ibanga elihanjwa ukukhanya onyakeni owodwa (unyaka okhanyayo) cishe liphindwe izikhathi ezingu-63.000 63 ibanga elihanjwa yiLanga ukuya eMhlabeni. Ngakho 150 izinkulungwane izikhathi XNUMX million km.
I-Exobiology: I-Proxima B
Okuseduze kakhulu I-proxima b, iyingxenye yesistimu ye-Proxima Centauri emthaleni wethu, i-Milky Way. I-Proxima b ikude ngeminyaka engu-4,2 yokukhanya futhi iyiplanethi yesishiyagalombili efana noMhlaba ngokwenkomba ye-ESI, isikali sokulinganisa somzimba esisetshenziswa ukuqhathanisa amanye amaplanethi noMhlaba. Inani lale nkomba liphakathi kuka-0 (akukho ukufana) no-1 (iplanethi iyafana noMhlaba) futhi ibalwa ngokusekelwe kububanzi, ukuminyana, isivinini sokuphunyuka kanye nezinga lokushisa elingaphezulu. I-Proxima b inenani le-ESI elingu-0,87 futhi ikhombisa ukuthi iplanethi ifana kakhulu noMhlaba. Nokho, le datha ayinikezi ulwazi mayelana nokuhlala kwayo.
Izinyanga
Ukufuna ukuphila emkhathini akugcini nje kuma-exoplanets, kodwa kuthinta namasathelayithi awo, izinyanga. Isibonelo singatholakala ngaphakathi nje kwesimiso sethu sonozungezilanga. Kukholakala ukuthi inyanga kaSaturn, i-enceladus, nenyanga kaJupiter, Europa, okungenzeka kube nokuphila.
Ibanga ukusuka elangeni Enceladusayikuvumeli ukuthi ithole imisebe yelanga eyanele ukuze izifudumeze, ngakho amazinga okushisa angaphezulu kwayo aphakathi kuka -128°C no -240°C: nakanjani akuyona indawo lapho ukuphila ngokuvamile bekungafunwa khona. Nokho, ngenxa yophenyo lweCassini kwatholakala ukuthi amanzi kanye nama- molecule ephilayo akhona kule nyanga eyiqhwa. Ukuhlaziya kubonise ukuthi i-nitrogen, i-carbon dioxide kanye ne-methane ikhona kujethi lomhwamuko ophuma phezulu. Ngenxa yalesi sizathu, kukholakala ukuthi ngaphansi kwendawo eqandisiwe kukhona ungqimba oluningi lwamanzi, lapho ama-molecule ahlukahlukene ancibilika, abhekele umsebenzi we-hydrothermal we-substrate kanye nama-geyser angaphezulu. Kungacatshangwa ukuthi lesi simo sithonywa ukuba khona okucatshangelwayo kwezinto eziphilayo ze-metanogenic.
Ngo-2018, abanye abacwaningi bazama ukwakha kabusha izimo ze-Enceladus ngokuhlolwa, okubonisa ukuthi i-microorganism. I-Methanothermococcus okinawensis ingaba nezici ezifanele zokuphila futhi ikhiqize i-methane ongqimbeni olungaphansi. Isiphetho salolu cwaningo sisitshela ukuthi izinto eziphilayo ezifanayo zingakwazi ukwenza lokhu, ngakho-ke empeleni zibe ku-Enceladus.
Imaphi amagciwane angaphila kwamanye amaplanethi?
Ama-microorganisms anamakhono athile ahlonzwa njengama-extremophiles ngoba avame ukuhlala ngaphansi kwezimo ezivimbela izinto eziphilayo eziyinkimbinkimbi. Kumele kuqashelwe ukuthi lezi zinambuzane ngokuvamile zihlala kulezi zimo, ngakho-ke kungacatshangwa ukuthi ziyaphila futhi zitholakala nasezimweni eziyinkimbinkimbi.
Okudume kakhulu emhlabeni we-biology ngokuqinisekile I-Thermus aquaticus, ekwazi ukukhula emazingeni okushisa angama-75 ° C; ngenxa yakhe kwakungenzeka ukuthuthukisa kakhulu indlela yokukhulisa i-DNA. Kunama-microorganisms amaningi anjalo, ngalinye eliye lajwayela isimo esisodwa noma ngaphezulu, ngaleyo ndlela libe yi-polyextremophilic.
Nazi izibonelo ezithakazelisayo:
- I-Picrophilus oshimae iphila ku-sulfate ezimweni ezine-acidic kakhulu ze-pH enenani elingu-0,6 kwezingu-14, elinamandla kune-hydrochloric acid.
- Thermococcus piezophilus uhlala kwalasha ngomfutho we-125 Mpa, ohambelana cishe ne-1275 kg esetshenziswa endaweni eyisentimitha eyodwa. Kuye kwaqinisekiswa ukuthi amanye ama-microorganisms ayakwazi ukuhlala esebenza nge-metabolic ngisho nangaphansi kwengcindezi ye-2000 Mpa;
- I-Halarsenatibacter silvermanii uhlala echibini eline-alkaline kakhulu lapho usawoti we-NaCl ungama-35% mg/L;
- I-Deinococcus radioduran s, kuze kube manje ibhekwa njengemodeli ye-microorganism yocwaningo lokumelana nemisebe ne-vacuum, i-polextremophile ekwazi ukusinda ezimweni zeplanethi i-Mars.
Kukhona ukuphila eMars?
I-Mars iyiplanethi yesine eqhelile kakhulu elangeni lethu, ngaphambi kokuba ibe nguMhlaba. Imishini eminingi yenziwe emashumini eminyaka amuva nje ukuyihlola nokwenza ucwaningo. I-NASA's Perseverance iyintsha kakhulu, isasebenza futhi kulindeleke ukuthi iphinde ingene ngo-2033.
Idatha yomhlabathi nezimo ku-Mars okwamanje azibonakali zithembisa i-exobiology. Ngo-2003, ithimba labacwaningi lihlonze umdlalo mayelana nokubunjwa kwenhlabathi phakathi kwesampula yomhlabathi eqoqwe yimishini yamaViking kanye nenhlabathi evela endaweni eqhelile ye-Atacama Desert eChile, futhi ngemva kwemizamo eminingana yathola ukuthi inhlabathi yayingafaneleki. nganoma yiluphi uhlobo lokutshalwa kwemvelo. Ngakho-ke kusengenzeka kuphi ukuba nethemba lokuthola iminonjana yokuphila ku-Mars?
ukuphila ngaphansi komhlaba
Ukutholwa kuka-2022 kunikeze izazi ze-exobiology amandla ekufuneni kwazo impilo yangaphandle. Lawa amakristalu amancane akhona kuma-rock inclusions enkabeni ye-Australia, aqala eminyakeni eyizigidi ezingu-830. Ngaphakathi kwalawa makristalu amancane, ama-organic compounds kanye nokuba khona kwamaseli e-prokaryotic kanye ne-eukaryotic aye ahlala egcinwe ngaphakathi kwale mvelo encane ahlonziwe. Ngokusho kochwepheshe, lezi zinhlobo zenhlabathi, noma ngabe imvelaphi ye-Terestrial noma Extraterrestrial, kufanele kubhekwe njengabasesingathi abangaba khona kuma-microorganisms amadala kanye nezinhlanganisela eziphilayo. Lokhu kuphakamisa ukusesha okungaba khona futhi uthole indawo kwamanye amaplanethi: indawo engaphansi.
Ngaphezu kwalokho, endaweni engaphansi isenzakalo se inyoka. Ukusabela kwamakhemikhali okwenzeka ngaphansi kwezimo ze-pH ye-alkaline nokuthi, ngenxa yokusebenzisana phakathi kwamanzi namadwala, kukhiphe izinhlanganisela ze-hydrogen, eziphilayo kanye ne-inorganic carbon. I-Serpentinization, ngokusho kwezazi ze-exobiologists, isakazeke ezindaweni zasemkhathini zesimiso sonozungezilanga, kuhlanganise neNyanga, futhi kucatshangwa ukuthi kungenzeka ibe nendima ebalulekile eMhlabeni, ivumela ukuphila kwezilwanyana ezithile ezincane.
Iziphetho mayelana ne-exobiology
Ucwaningo lwe-exobiology lusaqhubeka, ngo-Okthoba 2024 i-NASA i-aerospace agency izokwethula umgomo omusha: CLIPPER. Umgomo kuzoba ukusesha imikhondo yempilo kusuka kumajethi anesitimu akhishwa enye yezinyanga ezineqhwa zeJupiter: Europa.
Okwamanje, izinto eziphilayo ezihlala kwamanye amazwe azikaze zibonakale, kodwa kungenzeka ukuthi zikhona endaweni yonke angeke zikhishwe. Kodwa-ke, kufanele sicabangele ukuthi impilo ingakhula ngaphansi kwezimo ezihluke ngokuphelele kulezo zasemhlabeni, nokuthi ngenxa yalokho iyaguquguquka futhi iguquke ngezindlela esingazazi. Ukutholakala kwezinhlobo zezinto eziphilayo zangaphandle komhlaba kuzoletha ukunaka okukhulu okuvela emphakathini wesayensi kuya egatsheni le-exobiology, okuvula izindlela ezingakaze zihlolwe kuze kube manje.