Cishe usuyibonile inkanyezi edubulayo izikhathi ezingaphezu kwesisodwa. Kukhona ngisho nokuwa okukhulu kwe-meteor, njengama-Perseid. Akungabazeki ukuthi zinhle kakhulu ukuzibuka, kodwa uyazi ngempela ukuthi iyini inkanyezi edubulayo? Ubuwazi ukuthi kungenzeka ukuthi iyi-meteoroid? Hlala nathi ukuze ufunde ngezinhlobo ezahlukene ze-meteoroid ezenziwe ngazo.
Iyini i-meteor?
Ngokusho kwe-RAE, ama-meteorite "ayizingxenyana zendikimba yasezulwini eziwela eMhlabeni, noma kunoma iyiphi enye inkanyezi." Kusukela kule ncazelo kuyaqondakala ukuthi awekho ama-meteorite kuphela emhlabeni, kodwa ukuthi singawathola cishe kuzo zonke izindikimba zasezulwini zesimiso sonozungezilanga. Kodwa akuchazi ukuthi bavelaphi. Ngokocwaningo osekuyisikhathi eside lukhona, zingavela kuma-asteroids, izinkanyezi ezinomsila, ngisho nakwamanye amaplanethi.
Ngakho-ke, lapho lezi zingcezu ezincane zamatshe zingena emkhathini ngesikhathi somzila wazo, ziyaqhekeka, zishiye umkhondo okhanyayo: izinkanyezi ezidubulayo . Kodwa uma ucezu lungeluncane kangako futhi lukwazi ukusinda ekungqubuzaneni nomkhathi, luzoqonda ngqo emhlabathini njenge-bolide. Yile ngcezu yedwala esisindile esiyibiza ngokuthi i-meteorite.
Singasho ngokuqinisekile ukuthi ungqimba loMhlaba esilubiza ngokuthi umkhathi lusebenza njengesivikelo kulezi zicucu. Umkhathi uwungqimba lwegesi olumboze iplanethi futhi umphumela wawo ukuthi iningi lezinsongo ezingaba khona ziyahlakazeka ngaphandle kokufika phansi. Kodwa-ke, ngama-meteorite amakhulu kwenzeka ukuthi azophuka abe yizicucu ezincane, ezingashaya phansi. Lokhu kuyiqiniso kakhulu ngokwesayensi kangangokuthi kulinganiselwa ukuthi ngonyaka owodwa amathani angama-40.000 XNUMX ama-meteorite angawela eMhlabeni.
Kunjalo, iningi in microscopic futhi imperceptible ifomu. Kodwa kube khona, futhi kusazoqhubeka, izimo lapho ama-meteorite anobukhulu obuhloniphekile akwazile ukuwela phansi futhi atholakale futhi ahlaziywe. Ezinye zikhulu njenge-meteorite evela e-El Chaco (Argentina) ene-37.000 kg.
Izinhlobo zamameteorite
Kuvele ukuthi akuwona wonke ama-meteorite anokwakheka okufanayo. Siphinde sibe nesithakazelo ngemvelaphi yabo, ukubunjwa kwabo kanye neminyaka yabo, ngoba ngenxa yalezi zici, kungenzeka ukuhlukanisa. Njengoba isikhathi sesidlulile futhi nesayensi ithuthukile, kuye kwaba nokwenzeka ukusungula ukuhlukaniswa kwama-meteorite, kuye ngamakhemikhali, i-geological noma izici zokongiwa kwemvelo.
Ngenhloso yalesi sihloko, sikhethe ukuhlukaniswa okujwayelekile kakhulu ngokusekelwe emvelaphi kanye nokwakheka kwazo. Lezi yizinhlobo eziyinhloko zama-meteorite :
Ama-chondrite okuqala noma ama-meteorite
Kulinganiselwa ukuthi zisukela ekwakhiweni kweSistimu Yelanga , cishe eminyakeni eyizigidigidi ezingu-4.500 edlule, futhi azikaze zishintshe kusukela ngaleso sikhathi. Azibonisi zimpawu zokuthi ziye zadlula ezinqubweni zokuncibilika noma zokwehlukaniswa, futhi azizange zishintshwe yizimo zejiyoloji njengomoya, amanzi, noma amagagasi.
Lawa aqhelelene kakhulu ne-Solar System yethu futhi abalulekile ukutadisha ukwakheka kwamaplanethi. Lezi zingcezu zamatshe ziyizingcezu eziyigugu zesayensi. Ama-Chondrite abuye abizwe ngokuthi ama-meteorite akudala noma angahlanganisiwe futhi anesici esithile esingamaphesenti aphansi ensimbi, angaphansi kuka-10%.
Igama elithi chondrites livela ekumeni kwalolu hlobo lwedwala, elibonisa inani lezinhlayiya ezibukeka njengengilazi. Lawa ama-meteorite avame kakhulu futhi amelela ngaphezu kwama-85% awo wonke ama-meteorite atholakele.
Ngaphakathi kwalesi sigaba sama-Chondrites, singathola izinhlobo ezahlukene, ngenxa yokwakheka kwazo namaphesenti ensimbi:
ama-chondrites e-carbonaceous
Lawa ma-chondrite angama-5% kuphela ama-chondrite awele eMhlabeni. Ukwakheka kwayo kuvame ukuqukatha kuze kufike ku-5% wekhabhoni, kodwa kuvamile ukuthola amanzi angafika ku-20% kanye nezinye izinhlanganisela eziphilayo. Kuphinde kwatholakala ukuthi yizona ezinenani eliphakeme kakhulu lezinto eziguquguqukayo, yingakho kucatshangwa ukuthi zakha ukude kakhulu neLanga.
ama-chondrite ajwayelekile
Ziyikilasi elivame kakhulu lama-chondrite afinyelele eMhlabeni. Zakhiwe ngezinsimbi nama-silicates. Ngokuvamile zivela kuma-asteroid amancane futhi ngokuvamile ahlukaniswa ngokuya ngengxenye yensimbi equkethe.
Faka ama-chondrites
Lawa ama-meteorite angamatshe, ukwakheka kwawo ikakhulukazi i-mineral ebizwa ngokuthi i-enstatite (MgSiO3). Aziningi kakhulu, kodwa kuyaziwa ukuthi ziyizinsalela zamaminerali, okuvela kuwo iplanethi yethu, njengoba ukwakheka kwawo, phakathi kwama-meteorite awaziwayo, yiwo afana kakhulu nomhlaba.
Ngaleso sizathu, ososayensi beplanethi basikisela ukuthi ingxube yalezi zinhlobo zama-meteorite, ngenxa yenqubo yokuhlanganisa, kwakuyimvelaphi yombungu woMhlaba. Le thiyori iphinde ichaze isizathu sokushoda kwazo. Izingcezu ezimbalwa kuphela ezihlakazekile esifundeni lapho amaplanethi asemhlabeni akha ibhande eliyinhloko, futhi bambalwa kakhulu abehlele kithi besuka lapho.
ihlukaniswe noma ihlanganiswe
Lawa ma-meteorite aqala ngenxa yokuncibilika kwengxenye noma okuphelele kwemizimba evela kuyo. Lokhu kusho ukuthi avela emizimbeni emikhulu endaweni yonke, engalinganisa izinkulungwane zamakhilomitha ububanzi, futhi eye yadlula ezinqubweni ze-metamorphic ngaphakathi kwayo. Ngokusekelwe ekwakhekeni kwawo, izinhlobo ezintathu ezihlukile zama-meteorite zingabonakala : amatshe (noma ama-achondrite), amatshe-metallic, kanye namatshe.
ama-achondrites
Njengoba igama lawo lisho, ama-achondrite ayizinhlobo zama-meteorite angenawo ama-chondrules. Ngokuyinhloko angamatshe angcolile avela kwezinye izidumbu ku-Solar System. Ama-achondrite ahlukaniswe ngokwemvelaphi yawo.
Kutholwe ama-Achondrites avela ku-Mars (Shergotites, Nakhlites, Chassignites), iNyanga noma iVesta (Ecrites, Diogenites, Howardites). Kodwa iqiniso liwukuthi iningi laba nemvelaphi yalo emizimbeni esendaweni yonke engakaziwa.
I-Metallic
Ama-meteorite e-metallic yilawo ukwakheka kwawo kuyinsimbi engama-90%, ngokuvamile inhlanganisela yensimbi ne-nickel. Kuye kwatholakala ukuthi ngokuvamile zivela ezinkambeni zama-asteroids amakhulu, ngakho-ke kufanele zikhishwe lapho zithola umthelela omkhulu.
Ngokulandelayo, zihlukaniswa ngokwesakhiwo sazo. Ngakho-ke, ama-hexahedrite aqukethe i-nickel engu-4-6% kanye ne-iron engu-90%. Abizwa kanjalo ngoba akhiwe ngamakristalu e-cubic, hexahedral e-kamacite. Bese kuba nama-octahedrite, ane-nickel engu-6-14% futhi abonisa imigqa ye-Windmanstätten eyaziwayo. Lezi yizinhlobo ezivame kakhulu zama-meteorite ensimbi .
I-Rockmetal
Lezi yizinhlobo zama-meteorite ezakhiwe cishe ngesigamu sezinto zensimbi kanye nengxenye yezinto ezi-silicate. Kuye kwatholakala ukuthi zivela ngaphakathi kwama-asteroid amakhulu. Ngokusekelwe ekwakhekeni kwawo, ahlukaniswa njenge-pallasites kanye ne-mesosiderites.
Ama-Pallasite aphakathi kwezinhlobo ezinhle kakhulu zama-meteorite , abonisa inhlanganisela yezinsimbi, ikakhulukazi insimbi ne-nickel, kanye nama-silicates, ikakhulukazi i-olivine. Aqanjwe ngegama lesazi sezilwane saseJalimane kanye nesazi sezitshalo uPeter Simon Pallas, owathola isampula yokuqala yalolu hlobo lwe-meteorite eSiberia, eRussia, ngo-1772. Ngakolunye uhlangothi, ama-mesosiderites abonisa ingxubevange ehlukahlukene nengahlelekile yamaminerali njenge-pyroxene ne-plagioclase, kanye namakristalu e-nickel nensimbi.
Sithemba ukuthi lesi sihloko sikusizile ukuthi ufunde ukuhlonza izinhlobo ezahlukene zama-meteorite .