Ƙasar dutsen dutsen da ke tsakiyar Antarctica bai taɓa ƙunshi ƙananan ƙwayoyin cuta ba.
A karon farko, masana kimiyya sun gano cewa da alama babu rai a cikin ƙasa a saman duniya. Ƙasar ta fito ne daga iska guda biyu, tsaunin dutse a cikin Antarctica, mai nisan mil 300 daga Pole ta Kudu, inda dubban ƙafafu na kankara ke ratsa tsaunuka.
"Mutane koyaushe suna tunanin cewa ƙananan ƙwayoyin cuta suna da wuya kuma suna iya rayuwa a ko'ina," in ji Noah Firer, masanin ilimin halittu a Jami'ar Colorado Boulder wanda ƙungiyarsa ke nazarin ƙasa. Bayan haka, an samu kwayoyin halitta guda daya suna zaune a cikin iska mai zafi tare da yanayin zafi sama da digiri 200 na Fahrenheit, a cikin tabkuna da ke karkashin rabin mil na kankara a Antarctica, har ma da ƙafa 120,000 sama da stratosphere na duniya. Amma bayan aiki na shekara guda, Ferrer da dalibinsa na digiri na uku Nicholas Dragon har yanzu ba su sami alamun rayuwa a cikin ƙasan Antarctic da suka tattara ba.
Firer da Dragone sun yi nazarin ƙasa daga jeri 11 daban-daban na tsaunuka, suna wakiltar yanayi da yawa. Waɗanda ke fitowa daga ƙanana da ƙananan wuraren tsaunuka suna ɗauke da ƙwayoyin cuta da fungi. Amma a wasu tsaunuka na tsaunuka biyu mafi tsayi, bushewa kuma mafi sanyi babu alamun rayuwa.
"Ba za mu iya cewa ba su da haihuwa," in ji Ferrer. Masana ilimin halittu sun saba da gano miliyoyin kwayoyin halitta a cikin teaspoon na ƙasa. Saboda haka, ƙaramin adadi (misali sel masu aiki 100) na iya tserewa ganowa. "Amma kamar yadda muka sani, ba su ƙunshi wasu ƙwayoyin cuta ba."
Ko wasu ƙasa ba ta da rai ko kuma daga baya aka gano tana ɗauke da wasu sel masu rai, sabon binciken da aka buga kwanan nan a cikin mujallar JGR Biogeosciences zai iya taimakawa wajen neman rayuwa a duniyar Mars. Ƙasar Antarctic tana daskarewa har abada, cike da gishiri mai guba, kuma ba ta da ruwa mai yawa tsawon shekaru miliyan biyu-mai kama da ƙasar Martian.
An tattara su yayin balaguron balaguron tallafin Gidauniyar Kimiyya ta ƙasa a cikin Janairu 2018 zuwa yankuna masu nisa na tsaunin Transantarctic. Suna ratsa cikin tsakiyar nahiyar, inda suka kebe babban tudun polar da ke gabas da ƙanƙarar ƙanƙara a yamma. Masanan sun kafa sansani a kan Shackleton Glacier, bel ɗin jigilar ƙanƙara mai nisan mil 60 wanda ke gangarowa a cikin tudun duwatsu. Sun yi amfani da jirage masu saukar ungulu don tashi zuwa tsaunuka masu tsayi da tattara samfurori sama da ƙasa da glacier.
A cikin dumu-dumu, jike a gindin dusar ƙanƙara, ƙafar ƙanƙara ɗari sama da matakin teku, sun gano cewa ƙasar tana zaune ne da dabbobi ƙanana fiye da nau'in sesame: tsutsotsi masu kamanni, tardigrades ƙafa takwas, rotifers da ƙananan tsutsotsi. ake kira springtails. Kwari masu fuka-fuki. Waɗannan ƙasa maras ƙasƙanci, mai yashi sun ƙunshi ƙasa da kashi dubu ɗaya na adadin ƙwayoyin cuta da ake samu a cikin ciyawar da aka ɗora da kyau, wanda ya isa ya ba da abinci ga ƙananan ganyen da ke ɓoye a ƙasa.
Amma a hankali waɗannan alamun rayuwa sun ɓace yayin da ƙungiyar ta ziyarci tsaunuka masu zurfi a cikin glacier. A saman dusar ƙanƙara, sun ziyarci tsaunuka biyu—Mount Schroeder da Dutsen Roberts—wadanda ke da tsayin ƙafa 7,000.
Ziyarar da aka yi a Dutsen Schroeder na zalunci ne, in ji Byron Adams, masanin halittu a Jami'ar Brigham Young da ke Provo, Utah, wanda ya jagoranci aikin. Zazzabi a wannan ranar bazara yana kusa da 0°F. Guguwar hayaniya ta kwashe kankara da dusar ƙanƙara a hankali, ta bar tsaunuka babu kowa, abin da ke zama barazana ga ɗagawa da jifa da shebur ɗin lambun da suka kawo don tono yashi. Ƙasar tana cike da jajayen duwatsu masu aman wuta waɗanda iska da ruwan sama suka lalatar da su sama da ɗaruruwan miliyoyin shekaru, inda suka bar su a rami da gogewa.
Lokacin da masanan kimiyya suka ɗaga dutsen, sun gano cewa tushensa yana rufe da ɓawon farin gishiri—kristal mai guba na perchlorate, chlorate, da nitrate. Perchlorates da chlorates, gishiri masu lalata da ake amfani da su a cikin man roka da bleach masana'antu, ana kuma samun su da yawa a saman duniyar Mars. Ba tare da ruwan da zai wanke ba, gishiri ya taru a kan busassun tsaunukan Antarctic.
"Kamar samfurin Mars ne," in ji Adams. Lokacin da kuka manne felu a ciki, “kun san ku ne farkon abin da zai dagula ƙasa a ciki har abada—watakila miliyoyin shekaru.”
Masu binciken sun ba da shawarar cewa ko da a irin wannan tsayin tsayi da kuma yanayi mafi muni, za su iya samun rayayyun halittu a cikin ƙasa. Amma waɗannan tsammanin sun fara dusashewa a ƙarshen 2018, lokacin da Dragon yayi amfani da wata dabara da ake kira polymerase chain reaction (PCR) don gano ƙananan ƙwayoyin DNA a cikin datti. Dragon ya gwada samfurori 204 daga tsaunuka sama da ƙasa da glacier. Samfurori daga ƙananan, tsaunuka masu sanyi sun ba da adadi mai yawa na DNA; amma yawancin samfurori (20%) daga tsaunuka masu tsayi, ciki har da mafi yawan daga Dutsen Schroeder da Roberts Massif, ba a gwada su don kowane sakamako ba, yana nuna cewa sun ƙunshi ƙananan ƙananan ƙwayoyin cuta ko watakila babu ɗaya.
"Lokacin da ya fara nuna min wasu sakamako, na yi tunani, 'Wani abu ba daidai ba ne," in ji Ferrell. Ya yi tunanin cewa dole ne a sami wani abu da ba daidai ba tare da samfurin ko kayan aikin lab.
Dragon sai ya gudanar da jerin ƙarin gwaje-gwaje don neman alamun rayuwa. Ya yi maganin kasa da glucose don ganin ko wasu kwayoyin halitta a cikin kasa sun canza ta zuwa carbon dioxide. Ya yi kokarin gano wani sinadari mai suna ATP, wanda duk rayuwan duniya ke amfani da shi wajen adana makamashi. Na wasu watanni, ya horar da guda na ƙasa a daban-daban na gina jiki gaurayawan, kokarin shawo data data kasance microorganisms girma cikin mazauna.
"Nick ya jefa kwandon dafa abinci a waɗannan samfuran," in ji Ferrell. Duk da waɗannan gwaje-gwajen, har yanzu bai sami komai a wasu ƙasa ba. "Yana da ban mamaki sosai."
Jacqueline Gurdial, masanin ilimin halittu a Jami'ar Guelph a Kanada, ta kira sakamakon "mai ban sha'awa," musamman ƙoƙarin Dragon don sanin ko wane abu ne ke tasiri ga yiwuwar gano ƙananan ƙwayoyin cuta a cikin wani wuri. Ya gano cewa tsayin daka da yawan sinadarin chlorate sune mafi ƙarfin hasashen gazawar gano rayuwa. "Wannan bincike ne mai ban sha'awa," in ji Goodyear. "Wannan yana gaya mana abubuwa da yawa game da iyakokin rayuwa a Duniya."
Ba ta da cikakkiyar gamsuwa cewa ƙasarsu ba ta da rai, wani ɓangare saboda abubuwan da ta samu a wani yanki na Antarctica.
Shekaru da yawa da suka wuce, ta yi nazarin ƙasa daga irin wannan yanayi a cikin tsaunin Transantarctic, wani wuri mai nisan mil 500 daga arewa maso yammacin Shackleton Glacier da ake kira University Valley wanda mai yiwuwa ba shi da danshi mai mahimmanci ko narke yanayin tsawon shekaru 120,000. Lokacin da ta shuka shi tsawon watanni 20 a 23 ° F, yanayin zafi na rani a cikin kwarin, ƙasa ba ta nuna alamun rayuwa ba. Amma lokacin da ta zafafa samfuran ƙasa da ɗan digiri sama da daskarewa, wasu sun nuna haɓakar ƙwayoyin cuta.
Alal misali, masana kimiyya sun gano cewa ƙwayoyin ƙwayoyin cuta suna raye har bayan dubban shekaru a cikin glaciers. Lokacin da suka shiga tarko, ƙwayar tantanin halitta na iya raguwa sau miliyan. Suna shiga cikin yanayin da ba su ƙara girma ba, amma kawai suna gyara lalacewar DNA da hasken sararin samaniya ke shiga cikin kankara. Goodyear yayi hasashe cewa waɗannan "masu tsira da sannu-sannu" na iya zama waɗanda ta samu a Kwalejin Kwalejin - tana zargin cewa idan Dragone da Firer sun yi nazarin ƙasa sau 10, za su iya samun su a cikin Roberts Massif ko Schroeder Mountain.
Brent Christner, wanda ke nazarin ƙananan ƙwayoyin cuta na Antarctic a Jami'ar Florida a Gainesville, ya yi imanin cewa waɗannan ƙasa mai tsayi, busassun ƙasa za su iya taimakawa wajen inganta neman rayuwa a duniyar Mars.
Ya yi nuni da cewa, kumbon Viking 1 da Viking 2 da ya sauka a duniyar Mars a shekarar 1976, sun gudanar da gwaje-gwajen gano rayuwa bisa wani bangare na nazarin kasa da ke kusa da gabar tekun Antarctica, yankin da ake kira Dry Valleys. Wasu daga cikin waɗannan ƙasa suna jika daga ruwan narke a lokacin rani. Suna ƙunshi ba kawai ƙwayoyin cuta ba, amma a wasu wurare har da ƙananan tsutsotsi da sauran dabbobi.
Sabanin haka, mafi girma, busasshiyar ƙasa na Dutsen Roberts da Dutsen Schroeder na iya samar da mafi kyawun filayen gwaji don kayan aikin Martian.
"Sanarwar Mars ba ta da kyau," in ji Christner. "Babu wata kwayar halitta a duniya da za ta iya rayuwa a sama" - aƙalla saman inci ko biyu. Duk wani jirgin da zai je wurin domin neman rayuwa dole ne a shirya shi don yin aiki a wasu wurare mafi tsanani a duniya.
Haƙƙin mallaka © 1996–2015 National Geographic Society. Haƙƙin mallaka © National Geographic Partners, LLC, 2015-2023. An kiyaye duk haƙƙoƙi.