UStephen Hawking, u-Yuri Milner kanye noMark Zuckerberg bahola ibhodi labaqondisi ohlelweni olusha olubizwa ngeBreakthrough Starshot, ubuchwepheshe bayo obungase busetshenziswe ngelinye ilanga ukufinyelela isihlabani esingumakhelwane woMhlaba, U-Alpha Centauri. Kanye nokuba ithagethi "elula", njengoba ingenye yezinkanyezi eziseduze kakhulu nelanga, izazi zezinkanyezi bezilokhu zibuka omakhelwane bethu bezinkanyezi ukuze bathole amaplanethi anjengoMhlaba. U-Alpha Centauri uyinkanyezi yethu eseduze kakhulu, kodwa uma sikhuluma ngendawo, akusondeli kangako. Iqhele nge-light-year engaphezu kuka-4, noma amamayela ayizigidi eziyizinkulungwane ezingama-25. Inkinga ukuthi ukuhamba emkhathini, njengoba sikwazi, kuhamba kancane. Ukube umkhumbi-mkhathi we-Voyager ohamba ngokushesha kakhulu ushiye iplanethi yethu ngamamayela angu-11 ngomzuzwana lapho abantu besuka e-Afrika okokuqala, ngabe usufinyelele ku-Alpha Centauri manje.
Kulesi sihloko sikutshela konke odinga ukukwazi mayelana ne-Alpha Centauri, izici zayo nokubaluleka kwayo.
Uhlelo lwe-Alpha Centauri
Yinkanyezi eseduze kakhulu nelanga futhi ibonakala kuphela eningizimu nenkabazwe. Iyinkanyezi yesithathu ekhanya kakhulu Emhlabeni futhi iqukethe izinkanyezi ezimbalwa ezibukeka njengephoyinti elilodwa lokukhanya. Omakhelwane bezinkanyezi abaseduze kakhulu nelanga izinkanyezi ezintathu ohlelweni lwe-Alpha Centauri.
Izinkanyezi ezimbili eziyinhloko i-Alpha Centauri A kanye no-B, akha ipheya kanambambili. Ziyisilinganiso seminyaka yokukhanya engu-4,3 ukusuka eMhlabeni.. Inkanyezi yesithathu nguProxima Centauri. U-Alpha Centauri A no-B bahlangana njalo eminyakeni engama-80 emzileni ojwayelekile we-barycentric. Ibanga eliphakathi kwawo licishe libe yi-11 amayunithi ezinkanyezi (AU noma i-AU), cishe ibanga elifanayo esilithola phakathi kweLanga ne-Uranus. U-Proxima Centauri uyingxenye yesihlanu ye-light-year noma i-13.000 AU kusukela kwezinye izinkanyezi ezimbili, ibanga elinezazi zezinkanyezi ezibuza ukuthi kufanele yini ithathwe njengengxenye yohlelo olufanayo.
U-Alpha Centauri A uyinkanyezi yesine ekhanyayo njengoba ibonakala eMhlabeni, kodwa ukukhanya okuhlangene okuvela ku-Alpha Centauri A no-B kukhudlwana kancane, ngakho ngalowo mqondo uyinkanyezi yesithathu ekhanya kakhulu ebonakalayo esibhakabhakeni soMhlaba. Inkanyezi ephuzi i-Alpha Centauri A iwuhlobo lwenkanyezi efanayo nelanga lethu, kodwa inkulu kancane. Ngenxa yokuba seduze noMhlaba, ibonakala ikhanya esibhakabhakeni sethu. Izinga lokushisa elingaphezulu kwalo lingama-degree ambalwa e-Kelvin apholile kunalawo eLanga lethu, kodwa ububanzi bayo obukhulu kanye nendawo yonke kuyenza ibe ukukhanya okuphindwe izikhathi ezingu-1,6 kuneLanga.
Ilungu elincane kakhulu lesistimu, i-Alpha Centauri B ewolintshi, incane kancane kunelanga lethu futhi inohlobo lwe-K2. Ngenxa yezinga lokushisa elipholile kanye nohhafu kuphela wokukhanya kweLanga, i-Alpha Centauri B izokhanya ngokwayo njengenkanyezi engu-21 ekhanya kakhulu esibhakabhakeni sethu. Laba ababili ziyizingxenye ezikhanya kakhulu zesistimu, ezizungeza isikhungo esivamile samandla adonsela phansi njalo ngemva kweminyaka engama-80. Ama-orbit ane-elliptical kakhulu, nebanga eliphakathi kwezinkanyezi ezimbili lilinganiselwa ku-11 AU, noma ibanga loMhlaba neLanga.
Indawo nezinkanyezi ze-Alpha Centauri
Lesi simiso sezinkanyezi singesinye sezinhlelo zezinkanyezi eziseduze kakhulu nelanga, cishe iminyaka engu-4,37 yokukhanya ukusuka elangeni, okusho ukuthi amakhilomitha ayizigidi ezingama-41.300.
Izinkanyezi ezakha i-Alpha Centauri zintathu:
- U-Proxima Centauri: le nkanyezi ishisa uphethiloli kancane kancane, ngakho ingaba khona isikhathi eside. Ngo-Agasti 2016, kwamenyezelwa ukutholakala kweplanethi elingana noMhlaba ezungeza indawo okuhlalwa kuyo ezungeze i-Proxima Centauri, iplanethi ebizwa ngokuthi i-Proxima b. U-Proxima Centauri watholwa ngo-1915 isazi sezinkanyezi saseScotland uRobert Innes.
- Alpha Centauri A: Inkanyezi ewolintshi yohlobo lwe-K eyingxenye yesistimu yenkanyezi kanambambili. Iyakhanya, inkulu, futhi kukholakala ukuthi indala kunelanga. Ihlukaniswa njenge-dwarf ephuzi. Inomjikelezo wezinsuku ezingama-22.
- U-Alpha Centauri B: Kuyinkanyezi efana kakhulu nenkanyezi yethu enkulu kunazo zonke, iLanga, yohlobo lwe-spectral G, futhi izungeza emzileni weminyaka engaba ngu-80. Kukholakala ukuthi wazalwa ngesikhathi esifanayo no-A.
Ososayensi nezazi zezinkanyezi bathole ubufakazi obungqubuzanayo bokuba khona kwamaplanethi axhumeke kabili eMhlabeni e-Alpha Centauri. Okutholakele kuhlobene eduze nokutholakala kwe-exoplanet i-Alpha Centauri B ngo-2012. Le planethi inezici ezifana noMhlaba. Ukuba khona kwama-exoplanet kusitshela ukuthi kumelwe kube namaplanethi amaningi azungezayo ohlelweni olufanayo.
Ingabe kungaba khona ukuphila?
Amandla alesi simiso sokusingatha imihlaba ephethe ukuphila ahlale ehlaba umxhwele ososayensi, kodwa ama-exoplanets awaziwayo awakaze atholakale lapho, ngokwengxenye ngenxa yokuthi kuseduze kakhulu ukuba izazi zezinkanyezi zikwazi ukubona izinto zeplanethi endaweni. Kodwa ephepheni elishicilelwe ngoLwesithathu ku-Nature Communications, ithimba lamazwe ngamazwe lezazi zezinkanyezi lihlonze amasignesha agqamile wokuthwebula izithombe zendawo ehlala i-Alpha Centauri A, ngenxa ye-European Southern Observatory's (ESO) Very Large Telescope. UChili.
Isignali itholwe njengengxenye yephrojekthi ye-Alpha Centre Regional Near-Earth (NEAR), enikelwe yi-ESO kanye ne-Breakthrough Observing Astronomy Initiative. ngomnikelo olinganiselwa ku-2,8 million euros. Eyakamuva, esekelwa usozigidi waseRussia u-Yuri Milner, ifuna amaplanethi angamatshe, angangoMhlaba azungeze i-Alpha Centauri nezinye izinhlelo zezinkanyezi phakathi neminyaka engu-20 yokukhanya kwethu.
I-NEAR inika amandla ukuthuthukiswa okumbalwa kwesibonakude sase-Chile, okuhlanganisa ne-thermal chronograph, evimba ukukhanya kwenkanyezi futhi ibheke amasignesha okushisa avela ezintweni zeplanethi njengoba ebonisa ukukhanya kwenkanyezi. Ngemva kokuhlaziya amahora angu-100 edatha, uthole amasiginali azungeze u-Alpha Centauri A.
Iplanethi okukhulunywa ngayo ibingakaqanjwa namagama, futhi ubukhona bayo abuqinisekisiwe. Isignali entsha iphakamisa ukuthi icishe ilingane neNeptune, okusho ukuthi asikhulumi ngeplanethi efana noMhlaba, kodwa kunebhola elikhulu legesi eshisayo eliphindwe kahlanu kuya kasikhombisa kunoMhlaba. Esimeni sokucatshangelwa ukuthi yayinokuphila, yayingase ibonakale isesimweni samagciwane alenga emafwini. Isignali ingase futhi ibangelwe enye into, njengefu lothuli olushisayo lwe-cosmic, izinto ezikude kakhulu ezingemuva, noma ama-photon alahlekile.
Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana ne-Alpha Centauri nezici zayo.