Uphando Lokuqala Nge Vredefort Dome

© David Fleminger

Target: Earth

Kwiminyaka yoo 1950, kwakhutshwa incwadi egama liyi ‘Target: Earth’ nalapho umbhali waye kholelwa ekubeni iidinosaurs zathi zatshabalala ngenxa ye meteorite enkulu neyathi yantlitheka emhlabeni. Ngomnyaka ka 1959, uRobert Dietz wahlola iqela lendawo zoqhushumbo lwe ‘crypto-explosion’ waze wabona iintsalela ezibizwa ngee shattercones okokuqala. Lo ka Dietz waqikelela ukuba ezi shattercones zingaphinda zifunyanwe nase Vrederfort Dome, nalapho zathi zafunyanwa yi geologist yase Mzantsi Afrika kunyaka olandelayo. U-Dietz waqhubeka nokufumana iishattercones kwi Sudbury Structure enkulu ekwilizwe lase Canada.
Kwiminyaka yonke yoo 1950, uthotho lwe experimenti zase labhorathri nalapho iziqhushumbisi zaphoswa kwii ndawo ezithile, zenza kwalula ukukholelwa koluntlitheko. Ukuvavanywa kwe Nuclear nako kwadlala indima, ngethuba oososayensi befumanisa ukuba amandla akhutshwa ziziqhushumbisi ezinamandla anokunyibilikisa amatye angqongileyo adale ne
shock metamorphics, ebukufana naleyo ifumaneka kwii craters.

iAstro-Geologist

Kwiminyaka yoo 1960, amadoda achwechwela esibhakabhakeni aze aqalisa ukuthatha imifanekiso yesimo somhlaba-nyanga nge satellite. Oku kwavula iingqondo zososayensi kunye noluntu jikelele. Ngaxesha nye, i-‘astro-geologist’ esakhasayo egama lingu Gene Shoemaker yenza uphando olunzulu lwe Meteor Crater. Waze ke wathelekisa iziphumo kunye nohlalutyo lwezinye iindawo esele zisuka kuhlaselwa yi ntaba-mlilo (volcano). Wafumana ukungangqamani okuninzi, nokwaba bubungqina bokuba iMeteor Crater yayidalwe sisiganeko sokuntlitheka hayi yi ntaba-mlilo, icryptic okanye ngenye indlela.
Emva koku wabhengeza i-impact science, esithi iziganeko zontlitheko zingadala utshintsho olukhulu lokumila komhlaba kule planethi, kwaye ezi ziganeko zontlitheko zixhaphakile nakwezinye iiplanethi.

Lo ka Shoemaker waye wafundisa nee astronauts ze Apollo moon missions ngokumila kwe crater waze wabaxelela ukuba bakhangele namatye anika umdla elunar. Iindidi zamatye ababuya nazo enyangeni, zabonakalisa ukufana nalawo afumene ukuntlitheko apha eMhlabeni. Oku kwanceda kwevala ingxoxo yeplanethi. Namhlanje, uShoemaker waziwa kakhulu njengenxalenye yeqela elafumana icomet Shoemaker-Levy 9, neyantlitheka kwiplanethi iJupiter ngomnyaka ka 1994. uGene Shoemaker wabhubha ngomnyaka ka 1997 lwaze uthuthu lomzimba wakhe lwathunyelwa enyangeni nge Lunar Prospector probe. Ngelishwa le probe yawela enyangeni, oku kwakuzakuyivuyisa kakhulu lendedeba.

Ulwazi Oluphuhlayo

Bekhuthazwa lolulwazi luphuhlayo mayelana neziganeko zontlitheko, oososayensi kwihlabathi jikelele baqalisa ukuhlola iicraters(ezifana ne Nördlinger Ries Crater eGermany). Amatyeli ngamatyeli, bafumana iishattercone, amatye anyibilikileyo,iishock metamorphic kunye nezinye impawu zontlitheko, nesele zichazwe ngentla. Olu luhlu lwangqina ukuba ii-impact craters zakhula logama abaxhasi be cryptovolcanism baya berhoxa.

Translated by Zizipho Silwana