INyanga yoMhlaba icishe ibe yingxenye yesine yobubanzi boMhlaba. Lokho kungase kuzwakale kuyinto evamile uze uqhathanise amanye amaplanethi namasathelayithi awo: ngisho nezinyanga ezinkulu zeJupiter neSaturn zincane uma ziqhathaniswa nobubanzi bamaplanethi azo. Kumaplanethi ayisishiyagalombili, uMhlaba unenyanga enkulu kunazo zonke uma iqhathaniswa nobukhulu beplanethi eyizungezayo.
Lo mehluko udinga ukucaciswa ngezindlela ezimbili. INyanga yethu ayiyona isathelayithi enkulu kunazo zonke ngobukhulu bangempela, futhi uMhlaba neNyanga akubona laba abalingana kakhulu uma kufakwa namaplanethi amancane. Umngane kaPluto, uCharon, mkhulu kakhulu ngokwesilinganiso. Ngakho-ke umbuzo othakazelisayo awugcini ngokuthi “Inkulu kangakanani iNyanga?” kodwa uthi “Inkulu uma iqhathaniswa nani?”
Isilinganiso senza lo mbuzo ube indlela ewusizo yokuqhathanisa. Sisiza futhi ukuhlukanisa imiqondo emithathu evame ukudidaniswa: ubukhulu bomzimba, ukubaluleka kwawo ngokwamandla adonsela phansi, kanye nobukhulu obubonakala esibhakabhakeni. Imephu esebenzisanayo yesistimu yelanga ibonisa izindawo zamanje zamaplanethi; ukuqhathanisa okungezansi kuchaza esinye isici salolu hlelo—umehluko omkhulu phakathi kobukhulu bamaplanethi nobezinyanga zawo.
INyanga ingaphezu kwekota yobubanzi boMhlaba
Irediyasi yeNyanga ingu-1,737.4 km. Uma sisebenzisa irediyasi emaphakathi yoMhlaba ecishe ibe ngu-6,371 km, sihlukanisa irediyasi yeNyanga ngeyomhlaba bese sithola cishe u-0.273. Ngamanye amazwi, iNyanga icishe ibe u-27.3% wobubanzi boMhlaba. Isilinganiso siyafana uma sisebenzisa amarediyasi noma amadiamitha, ngoba ukuphinda kabili kokubili kokulinganisa akushintshi isilinganiso sawo.
Cabanga ngoMhlaba njengebhola elingamasentimitha angu-30 ububanzi. Ngaleso sikali, iNyanga ibingaba cishe ngamasentimitha angu-8.2 ububanzi: isondele kusawolintshi omkhulu kunobuhlalu obuncane. Lona ngumngane omkhulu ngokumangalisayo. Kodwa le modeli iveza nephutha elivamile emifanekisweni. Uma izikhungo zamabhola zihlukaniswe ibanga eliphakathi nendawo phakathi koMhlaba neNyanga elingu-384,400 km, bezizoba cishe ngamamitha angu-9.1 ukusuka kwenye kwenye. Isithombe esizibonisa zicishe zithintane singase sigcine izilinganiso zobukhulu bazo kodwa sicindezele kakhulu isikhala esiphakathi kwazo.
Ububanzi buyindlela eyodwa kuphela yokukala lobu budlelwano. INyanga inesisindo esicishe sibe ingxenye eyodwa kwezingu-81 yesisindo soMhlaba, noma cishe u-1.2%, hhayi u-27.3%. Umthamo ukhula ngokwe-cube yobubanzi: into enobubanzi obungu-0.273 kunobunye inomthamo olingana cishe no-0.020 kuphela, uma kucatshangwa ukuthi inomumo ofanayo. Lokho kucishe kube u-2%.
Umehluko osele ubangelwa ukuminyana. Ngokwesilinganiso, iNyanga ayiminyene njengoMhlaba, onomnyombo omkhulu ocebile ngensimbi ofaka isandla esikhulu esisindweni sawo. Ngakho-ke inyanga ingabonakala inkulu kakhulu eceleni kweplanethi yayo kodwa ingasondeli ekubeni umlingani olingana nayo ngokwamandla adonsela phansi. Kubalulekile ukuhlukanisa ububanzi nesisindo uma kuxoxwa ngokuthi uMhlaba neNyanga bafana yini neplanethi ekabili.
Izinyanga ezinkulu zingaba abangane abancane uma ziqhathaniswa namaplanethi azo
IGanymede yeJupiter iyinyanga enkulu kunazo zonke kuSolar System, inobubanzi obucishe bube ngu-5,268 km. ITitan yeSaturn ilandela, inobubanzi obucishe bube ngu-5,149 km. Zombili zibanzi kuneMercury, futhi zombili zibanzi kakhulu kuneNyanga yethu, enobubanzi obungu-3,474.8 km. Nokho, azikho ezenza amaplanethi azo abonakale emancane.
Uma kusetshenziswa amadiamitha amaphakathi, iGanymede icishe ibe u-3.8% kuphela wobubanzi beJupiter. ITitan icishe ibe u-4.4% wobubanzi beSaturn. Ngakho-ke isilinganiso sikaMhlaba esingu-27.3% siphindaphindeke ngaphezu kwezikhathi eziyisithupha uma siqhathaniswa nanoma yisiphi kulezi zilinganiso. Lokhu akusho ukuthi iNyanga yethu inkulu ngokuphindwe kasithupha; kusho ukuthi ubukhulu bayo ngokwesilinganiso uma iqhathaniswa neplanethi yayo bukhulu ngokuphindwe kasithupha nangaphezulu.
INeptune inikeza esinye isibonelo esiwusizo. Inyanga yayo enkulu kunazo zonke, iTriton, icishe ibe u-5.5% wobubanzi beNeptune. Leso isilinganiso esikhulu kuneseGanymede noma iTitan, kodwa sisengaphansi kakhulu kwesikaMhlaba neNyanga. IMars yona isekugcineni okuphambene: izinyanga zayo ezimbili ezincane nezingajwayelekile zincane kakhulu uma ziqhathaniswa neplanethi.
Lokhu kuqhathanisa kuchaza ukuthi kungani ukubeka izinyanga ngokulandelana kobubanzi kungaphenduli umbuzo wokuthi yiluphi uhlelo lwamaplanethi olunomngane ogqama kakhulu. INyanga yethu ingeyesihlanu ngobukhulu bangempela phakathi kwezinyanga zeSolar System, kodwa ingeyokuqala uma iqhathaniswa neplanethi yayo phakathi kwamaplanethi ayisishiyagalombili. Ukuze uthole uhlu olubanzi lwamasathelayithi, bheka umhlahlandlela wezinyanga zeSolar System; umehluko obalulekile lapha uphakathi kokubeka ngokobukhulu bangempela nokusebenzisa isilinganiso.
Ingabe lokho kwenza uMhlaba neNyanga kube yiplanethi ekabili?
“Iplanethi ekabili” incazelo ehehayo, kodwa ayinayo incazelo esemthethweni eyamukelwa umhlaba wonke. Olunye uvivinyo oluphakanyisiwe lubheka indawo lapho kutholakala khona isikhungo esivamile sesisindo sale mizimba emibili. Yomibili izungeza leli phuzu, elibizwa ngokuthi ibharisenta; umzimba omncane awuzungezi umzimba omkhulu onganyakazi nhlobo.
KuMhlaba neNyanga, ibharisenta ingaphakathi koMhlaba. Ungalinganisela indawo ekuyo usebenzisa isilinganiso sezisindo. Uma uMhlaba unesisindo esiphindwe cishe izikhathi ezingu-81 kuneseNyanga, ibharisenta iqhele ngebanga elilingana cishe nengxenye eyodwa kwezingu-82 yebanga eliphakathi kwezikhungo zayo zombili ukusuka esikhungweni soMhlaba. Uma kusetshenziswa ibanga elimaphakathi elingu-384,400 km, sithola cishe u-4,700 km. Lokho kungaphansi kwerediyasi yoMhlaba ecishe ibe ngu-6,371 km, ngakho kule zibalo ezenziwe zaba lula, leli phuzu litholakala cishe u-1,700 km ngaphansi kobuso.
Manje ake siqhathanise uPluto noCharon. UCharon ucishe abe yingxenye yobubanzi bukaPluto futhi unesisindo esicishe sibe ingxenye eyodwa kwezingu-8 sesikaPluto. Ibharisenta yabo ingaphandle kukaPluto, okubenza babe isibonelo esiqine kakhulu sababili abahambisana njengezindikimba ezimbili. UPluto uhlukaniswa njengeplanethi encane, ngakho lokhu akuguquli isimo esikhethekile soMhlaba phakathi kwamaplanethi ayisishiyagalombili.
Ukuhlola ibharisenta kuyasiza, kodwa akuwona umthetho ophelele wokuhlukanisa. Indawo yayo incike ebangeni kanye nasesisindweni: uma le mizimba emibili isuswa iqhelelane, ibharisenta isuka kude kakhulu nesikhungo ngasinye. Ngakho-ke, ukuba nephuzu elingaphandle komzimba omkhulu kukodwa akusho ukuthi isimo “seplanethi ekabili” sesamukelwe umhlaba wonke. Ngokwesiko, uMhlaba uyiplanethi kanti iNyanga iyisathelayithi yawo yemvelo, naphezu kobubanzi obukhulu ngokungajwayelekile beNyanga uma buqhathaniswa nobukaMhlaba.
Umkhondo wokuthi iNyanga yakheka kanjani
Ubukhulu beNyanga obukhulu buyinto eyodwa kweziningana okufanele ichazwe yithiyori ngemvelaphi yayo. Incazelo ehamba phambili ithi kwaba nokushayisana okukhulu: ekuqaleni komlando woMhlaba, ukushayisana okukhulu kwaphonsa izinto ezazungeza uMhlaba emkhathini, iNyanga yase yakheka ngezinsalela ezazizungeza. Umqondo oyinhloko usekelwa ubufakazi obuqinile, kodwa izimo eziqondile zokushayisana kanye nokuguquka okwalandela kuseyizihloko zocwaningo.
Ubukhulu bodwa abufakazeli leyo ndaba. Ososayensi bacabangela nomfutho we-angular wesistimu, umnyombo wensimbi weNyanga omncane uma uqhathaniswa, kanye nokufana kwamakhemikhali nama-isotopu phakathi kwezinto zasemhlabeni nezasenyangeni. Incazelo ephumelelayo kufanele ichaze konke lokhu okubonwayo ndawonye, kunokuba ivele ikhiqize isathelayithi enkulu ekulingiseni ngekhompyutha.
Lokhu kuhlukile emcabangweni ojwayelekile ngezinyanga ezinkulu nezivamile zamaplanethi amakhulu, okucatshangwa ukuthi zakheka ngaphakathi kwamadiski egesi nezinto eziqinile ezazizungeze amaplanethi ayekhula. Izimo ezihlukene zokwakheka zingadala izilinganiso ezihlukene phakathi kweplanethi nabangane bayo. Akudingekile ukuba lonke uhlelo lwamaplanethi lube ikhophi elilinganiswe kabusha lamanye.
Kufanele futhi kuhlukaniswe ukwakheka nokuguquka okwenzeka kamuva. Ukusebenzisana kwamandla olwandle kuye kwaguqula uhlelo loMhlaba neNyanga ngokuhamba kwesikhathi, futhi iNyanga iya iqhela eMhlabeni cishe ngo-3.8 cm ngonyaka. Lokho kushintsha ibanga eliphakathi kwazo, hhayi isilinganiso sobubanzi bazo. Lokhu kusebenzisana kusiza futhi ukuchaza ubudlelwano bazo obuvumelanisiwe bokuzungeza nokuphenduka, okuchazwe kokuthi kungani sihlala sibona uhlangothi olufanayo lweNyanga.
Kungani umngane omkhulu usabonakala umncane esibhakabhakeni
Ubukhulu beNyanga uma iqhathaniswa noMhlaba abufani nobukhulu obubonakala kumuntu obuka eseMhlabeni. Okubalulekile ekubonakaleni ububanzi beNyanga buhlukaniswe ngebanga elikude nawe. Uma kusetshenziswa ububanzi bayo obungu-3,474.8 km nebanga elimaphakathi elingu-384,400 km phakathi kwezikhungo zoMhlaba neNyanga, kutholakala ububanzi obubonakalayo obucishe bube ngu-0.52 degrees. Lesi isilinganiso esiwusizo esingesona esiqondile, hhayi isibikezelo esiqondile sendawo ethile yokubuka.
Yingakho umngane ongaphezu kwekota yobubanzi boMhlaba engathatha indawo encane kuphela esibhakabhakeni. Isikhala esiphakathi kwale mizimba sikhulu kakhulu uma siqhathaniswa nobubanzi banoma yimuphi kuyo. Uma iNyanga ibikude kakhulu, ibingabonakala incane ngaphandle kokuba inciphe ngokomzimba noma ilahlekelwe isilinganiso sayo sobukhulu obukhulu ngokungajwayelekile uma iqhathaniswa noMhlaba.
Lo mehluko unikeza indlela ewusizo yokuhlola izithombe zeNyanga eziqhathaniswayo. Izithombe ezithathwe ngobude obuhlukene be-focal, ezisikiwe ngezindlela ezahlukene noma ezinezinto ezingaphambili ezibekwe ngendlela ehlukile azikwazi ukufakazela ushintsho kubukhulu bangempela beNyanga. Ukuqhathanisa okunenjongo kobubanzi obubonakalayo kudinga isikali sesithombe esingaguquki. Amadeshibhodi eNyanga asemadolobheni abonisa ibanga, ukuphakama ne-azimuth kanye nesigaba nokukhanya kweNyanga, okukunika ulwazi oluwusizo lokurekhoda lokho okubonile. Gcina indlela yokusetha ikhamera ingashintshi, rekhoda ibanga, bese ungacwaninga ukushintsha kobukhulu obubonakalayo beNyanga ngaphandle kokukudidanisa nombuzo obaluleke kakhulu wokuthi umngane wethu mkhulu kangakanani uma eqhathaniswa noMhlaba.