Riaan Izazi zezinkanyezi zithole ubufakazi bokuqala bentaba-mlilo eqhumayo eVenus, zisebenzisa izithombe zekhompyutha ezathathwa eminyakeni engaphezu kwengu-30 edlule umkhumbi-mkhathi weNASA.
Eyethulwe ngo-May 1989, i-Magellan probe yaba eyokuqala yohlobo lwayo ukudweba cishe yonke indawo yeVenus (njengamaphesenti angu-98) isebenzisa i-radar. Umkhumbi-mkhathi awusekho – waphahlazeka emhlabeni ngo-1994. Cishe ama-gigabits angu-1,200 wedatha – ngaphezu kwayo yonke imisebenzi yangaphambili yeplanethi ye-NASA ihlangene – yavuselelwa ngaphambi kokuphahlazeka, futhi lolo lwazi luwusizo kuze kube namuhla.
Abacwaningi abasebenza ngomkhumbi-mkhathi we-NASA i-VERITAS*, okulindeleke ukuba wethule phakathi neminyaka eyishumi ukuze bahlole i-Venus, banqume ukumba intaba yama-CD-ROM aqukethe inqolobane yolwazi ethathwe ku-Magellan ukuze bahlole umsebenzi wentaba-mlilo kule planethi.
“Bengingakulindele ngempela ukuphumelela, kodwa ngemuva kwamahora angaba ngu-200 wokuqhathanisa ngesandla izithombe zemizungezo ehlukene ye-Magellan, ngabona izithombe ezimbili zesifunda esifanayo ezithathwe izinyanga eziyisishiyagalombili zihlukene zibonisa izinguquko eziphawulekayo ze-geological ezibangelwa ukuqhuma,” kusho Robert Herrick, uprofesa we-geophysics wase-University of Alaska Fairbanks futhi oyilungu lethimba lesayensi le-VERITAS.
Izithombe zithathwe e-Atla Regio – indawo eseduze nenkabazwe yaseVenus okuyikhaya lezintaba-mlilo ezimbili ezinkulu: i-Ozza Mons ne-Maat Mons, elinganiselwa kumakhulu amakhilomitha ububanzi. Izithombe ezithathwe phakathi kukaFebhuwari no-Okthoba 1991 zikhombisa ukuthi uMaat Mons wayesebenza ngaleso sikhathi.
Isithombe esidala sibonisa okubukeka njengembobo enodaka olubizela phansi emaceleni ayo endaweni enesilinganiso esingaphansi kwekhilomitha-skwele (amakhilomitha-skwele angu-2.6). Eyakamuva yabonisa ukuthi imbobo efanayo ishintshile, iphindwe kabili ngosayizi, futhi igcwele udaka. Izithombe zithathwe ngama-engeli ahlukene, nokho, okwenza kube nzima ngezazi zezinkanyezi ukuqhathanisa ngqo.
Singathola ukubukeka okufanele eminyakeni embalwa – Isithombe esakhiwe ngekhompyutha se-3D sentaba-mlilo i-Maat Mons kuVenus. Ikhredithi yesithombe: NASA JPL-Caltech (Umthombo)
U-Herrick nozakwabo bakhiphe idatha ezithombeni zikaMagellan ukuze bafanekisele umsebenzi wesikhala, balungise izithombe futhi bazenze zibonakale sengathi zithathwe embonweni ofanayo ngokuqondile. Imininingwane eyengeziwe ngocwaningo ingatholakala ephepheni eshicilelwe phakathi Isayensi ngolwesithathu.
“Izifaniso ezimbalwa kuphela ezihambisana nemifanekiso, futhi isimo okungenzeka kakhulu ukuthi kwenzeka intaba-mlilo endaweni yeVenus ngesikhathi somsebenzi kaMagellan,” kusho uScott Hensley, usosayensi wephrojekthi ye-VERITAS kanye nochwepheshe wokutadisha idatha ye-radar. Ezinye izimo ezingaba khona ezimodelayo – njengokudilika komhlaba, isibonelo – azizange zifane nemifanekiso yokugcina.
“Nakuba leli kuyiphuzu elilodwa nje ledatha yawo wonke amaplanethi, liqinisekisa ukuthi kunomsebenzi wesimanje wokuma komhlaba,” esho.
Ubuciko be-VERITAS kufanele busize izazi zezinkanyezi zisize ekucaciseni ukuthi kwenzakalani ku-Venus ngokuthwebula amamephu anemininingwane engeziwe e-3D yendawo yase-Venusian kusetshenziswa ubuchwepheshe be-radar obuthuthuke kakhulu. Izophinde iphathe amathuluzi akwazi ukukala inkundla yamandla adonsela phansi ukuze ihlaziye ingaphakathi layo, okuzonikeza ukuqonda ngezinqubo zayo zokuma komhlaba.
“IVenus iwumhlaba ongaqondakali, futhi uMagellan wagcona amathuba amaningi,” kusho uJennifer Whitten, isekela lomphenyi omkhulu we-VERITAS eTulane University eNew Orleans. “Manje njengoba sesiqiniseka kakhulu ukuthi iplanethi yaqhuma intaba-mlilo eminyakeni engu-30 kuphela edlule, lokhu ukubuka kuqala okuncane kokutholwa yi-VERITAS emangalisayo.”
Sekuyisikhathi eside izazi zezinkanyezi zikhangwa iplanethi yesibili kuSolar System. Ubukhulu kanye nokwakheka kwawo kuyafana noMhlaba futhi kungenzeka ukuthi wakheke ngesikhathi esifanayo. Kodwa indawo ezungezile iyashisa futhi inenkungu ngenxa yomphumela we-greenhouse, lapho amafu ayo aminyene abamba ukushisa. Ososayensi bakholelwa ukuthi iVenus iyisibonelo sokuthi umhlaba ungashintsha kanjani uma isimo sezulu siqhubeka nokufudumala.
I-ESA, i-Roscosmos yaseRussia, kanye ne-India’s Space Research Organisation nazo zihlela ukuthunyelwa kweVenus. Owokuqala ngqa umsebenzi wangasese emhlabeni kusukela ekuqaleni kwe-US i-Rocket Lab kulindeleke ukuthi yethulwe ngoMeyi kulo nyaka. ®
* Imele i-Venus Emissivity, i-Radio science, i-InSAR, i-Topography, kanye ne-Spectroscopy, eyakhiwe ngendlela emangalisayo futhi exakile – kodwa i-NASA isebenzisa ezinye zezingqondo ezinkulu kakhulu ukuze iqhamuke nama-acronyms apholile.
