menya umubumbe mushya ushobora kubonekaho ubuzima
Indebakure (Telescope) ya NASA yitwa James Webb ishobora kuba yavumbuye igisa n’ikimenyetso cy’ubuzima ku mubumbe wa kure cyane.
Ishobora kuba yabonye ‘molecule’ yitwa dimethyl sulphide (DMS). Ku Isi, nibura, iyi itangwa gusa n’ubuzima.
Abashakashatsi bavuga ko iyo yabonetse ku mubumbe uri mu ntera ya ‘light years’ 120 uvuye ku isi – ‘light year’ imwe ireshya na kilometero tiriyari icyenda. Bavuga ko hakenewe izindi ‘data’ zo gushimangira koko igisa n’iyo ‘molecule’ cyabonetse.
Abashakashatsi babonye kandi imyuka ya methane na CO2 mu kirere cy’uwo mubumbe.
Kuboneka kw’iyo myuka kwaba gusobanuye ko uwo mubumbe, wiswe K2-18b, ufite inyanja y’amazi.
Prof Nikku Madhusudhan wo muri University of Cambridge, wari ukuriye ubu bushakashatsi, yabwiye BBC ko ikipe ye yose “yatangaye” ubwo babonaga ibi.
Yagize ati: “Ku Isi, DMS itangwa gusa n’ubuzima. Itumukira mu kirere cy’isi ivuye mu bidukijije byo mu nyanja.”
Gusa Prof Nikku asobanura uko kuvumbura DMS nk’ibitaremezwa nta gushidikanya, ko andi makuru (data) agikenewe ngo bemeze nta gushidikanya ko ihari. Ibizava muri ayo makuru byitezwe mu gihe cy’umwaka.
Ati: “Nibyemezwa, bizaba ari ikintu gikomeye cyane kandi ndumva mfite inshingano yo kumenya neza ko ari ukuri mu gihe ubu turi kuvuga iki kintu gikomeye gutya.”
Ni ubwa mbere abahanga mu by’isanzure babonye igishobora kuba ari DMS ku mubumbe uzenguruka inyenyeri ya kure. Ariko barimo gufatana ubwitonzi ibyo babonye, kuko mu 2020 abahanga bavuze ko babonye mu kirere cya Venus indi ‘molecule’ yitwa phosphine, ishobora kuba iva ku binyabuzima ariko hashize umwaka ibi bigibwaho impaka.
Nubwo bimeze uko, Dr Robert Massey, umukuru wungirije wa Royal Astronomical Society i London kandi udafite aho ahuriye n’ubu bushakashatsi, yavuze ko ashishikajwe n’ibi byabonetse.
Yagize ati: “Buhoro buhoro turagenda tugana aho tuzashobora gusubiza cya kibazo gikomeye niba turi twenyine mu isanzure cyangwa hari n’abandi.”
Yongeraho ati: “Mfite icyizere ko umunsi umwe tuzabona ikimenyetso cy’ubuzima. Wenda gishobora kuba ari iki, wenda mu myaka 10 cyangwa se 50 tuzabona ikimenyetso gitanga igisobanuro gisobanutse.”
James Webb Space Telescope (JWST) ibasha kubona no gusesengura urumuri ruciye mu kirere cy’imibumbe iri kure cyane mu isanzure. Urwo rumuri ruba rwifitemo ibinyabutabire bigira za ‘molecules’ – nk’uko ubona uburyo umwiburungushure ukora ishusho y’umukororombya mu rumuri ruwunyuzemo. Abashakashatsi babasha gusesengura no kureba ibigize urumuri rwose mu kirere cy’imibumbe ya kure cyane.
Ikigira ubu bushakashatsi umwihariko ni uko uriya mubumbe uri mu birometero miliyari miliyoni 1.1 kure yacu, bityo ingano y’urumuri igera kuri iriya ndebakure ikaba ari nto cyane.
Hamwe na DMS, ibisa n’imyuka myinshi ya methane na carbon dioxide yahabonetse birushaho gutanga icyizere.
Imyuka ya CO2 na methane mu kirere iba kenshi ahari inyanja y’amazi n’ikirere gikungahaye ku myuka ya hydrogen. Indebakure ya mbere yitwa Hubble ya Nasa – yasimbuwe na JWST – mbere yari yarabonye kuri uwo mubumbe imyuka y’amazi, ariyo mpamvu uwo mubumbe ari umwe mu ya mbere yahise ikorwaho ubushakashatsi bwimbitse na JWST, ariko kuba haba hariyo inyanja ni intambwe itaraterwa.
Ubushobozi bw’umubumbe bwo kwakira ubuzima buva ku bipimo by’ubushyuhe (temperature), no kuba hari carbon hamwe wenda n’amazi asukika.
Ibyabonywe na JWST bisa n’ibyerekana ko K2-18b yujuje ibyo byose. Gusa kuba gusa umubumbe usa n’uwashobora kwakira ubuzima ntibisobanuye ko bishoboka, ariyo mpamvu kuba hashobora kuba hariyo DMS ari ibintu biteye amatsiko.
Igituma uyu mubumbe urushaho kuba utangaje ni uko udateye nk’Isi, uri mu yitwa imibumbe y’urubuye yavumbuwe mu izenguruka inyenyeri (nk’izuba) za kure icyekerwaho ubuzima. K2-18b ikubye hafi inshuro umunani Isi mu bunini.
Exoplanets – imibumbe izenguruka izindi nyenyeri – ifite ingano iri hagati y’isi na Neptune, itandukanye n’indi yose mu nyenyeri zizenguruka izuba (solar system). Ibi bivuga ko iyi mibumbe bita ‘sub-Neptune’ ibyayo bitazwiho byinshi, cyane cyane imiterere y’ibirere (ikirere) byayo, nk’uko bivugwa na Dr Subhajit Sarkar wa Cardiff University, undi wo mu itsinda riri gusesengura ubu bushakashatsi.
Ati: “Nubwo umubumbe nk’uyu (K2-18b) utabaho muri ‘solar system’, sub-Neptunes ni imibumbe iboneka cyane muri uru rujeje (galaxy) rwacu.
“Kugeza ubu twabonye ibimenyetso bihagije by’uko hashobora kuba ubuzima, ibi byatumye dushaka za molecules ziri mu kirere cyayo.”
