Ukugqama Kwemijikelezo Yeplanethi
Uma sicabanga ngamaplanethi azungeza izinkanyezi, isithombe esivame ukufika engqondweni ngesezindlela ezihlelekile nezizinzile eziyindilinga. Eqinisweni, iningi lemizila yamaplanethi ayizindilinga ngokuphelele. Ngokuvamile ziyizindilinga—njengendilinga “eyeluliwe” ohlangothini olulodwa. Isilinganiso sokuthi i-ellipse “i-elliptical” kangakanani sibizwa ngokuthi ukungavamile komjikelezo. Lo mqondo ubonakala ulula, kodwa unemiphumela ejulile: uthinta ukuhlukahluka kwebanga leplanethi nenkanyezi yayo, izinguquko esivinini sayo sokuzungeza, ngisho nesimo sezulu sayo esingaba khona kanye nokuhlala kwayo.
Kuyini ukungaziphathi ngendlela ehlukile?
Ngokuvamile, i-eccentricity (e) iyinombolo echaza ukuma komjikelezo:
– e = 0 kusho ukuthi umjikelezo uyindilinga ephelele.
– 0 < e < 1 kusho umjikelezo we-elliptical (lokhu kuvame kakhulu kumaplanethi). - e = 1 kusho umjikelezo we-parabolic (into idlula kanye futhi ingabuyi; isibonelo, ama-comet athile). - e > 1 kusho umjikelezo we-hyperbolic (into ivela kude bese ihamba unomphela).
Kumaplanethi asohlelweni lwelanga, inani lika-e liphakathi kuka-0 nangaphansi kuka-1, ngakho-ke wonke anemizila ye-elliptical. Kodwa-ke, izinga "lokugoba" kwala ma-ellipses liyahlukahluka.
I-Ellipse, i-focus, i-perihelion, kanye ne-aphelion
I-elliptical orbit inamaphuzu amabili aqondile abizwa ngokuthi i-foci. Uma kwenzeka iplanethi ezungeza iLanga, iLanga ligxile kakhulu, hhayi enkabeni ye-ellipse. Yingakho ibanga leplanethi ukusuka eLangeni lishintsha kulo lonke umjikelezo walo.
Izikhundla ezimbili ezibalulekile ku-orbit yilezi:
– I-Perihelion: indawo eseduze kakhulu neLanga yeplanethi
– I-Aphelion: indawo ekude kakhulu yeplanethi ukusuka eLangeni
Uma ubukhulu bokungavamile bukhula, umehluko omkhulu phakathi kwebanga phakathi kwe-perihelion ne-aphelion uba mkhulu.
Ukugxila kwe-Eccentricity kanye nemithetho kaKepler
Ukuma kwe-eccentricity akumi yodwa. Kuhlobene nendlela amaplanethi ahamba ngayo ngokweMithetho kaKepler, ikakhulukazi umthetho wesibili: umugqa ongokomfanekiso oxhumanisa iplanethi neLanga ukhipha izindawo ezilinganayo ngezikhathi ezilinganayo. Ngenxa yalokho, lapho iplanethi iseduze ne-perihelion, ihamba ngokushesha; uma iseduze ne-aphelion, ihamba kancane. Lokhu kuchaza ukuthi kungani "ijubane le-orbital" lingeyona into efanayo ye-elliptical orbit.
Ezindaweni ezicishe zibe yindilinga (u-e ophansi), izinguquko zesivinini kanye nebanga azibonakali. Kodwa ezindabeni ezingavamile (u-e ophakeme), umehluko ungaba mkhulu kakhulu.
Izibonelo zokungajwayelekile ohlelweni lwelanga
Amaplanethi ohlelweni lwelanga anamanani ahlukahlukene okungavamile. Nasi isifinyezo esijwayelekile (izinombolo zingase zilinganiswe):
– I-Venus: iseduze kakhulu nendilinga (e ~ 0,007)
– Umhlaba: cishe uyindilinga (e ~ 0,017)
– I-Mars: okusaqanda kakhulu (e ~ 0,093)
– I-Mercury: iplanethi engavamile kakhulu (e ~ 0,206)
Umhlaba uvame ukubhekwa njengonomjikelezo "oyindilinga", kodwa usalokhu u-elliptical. Umehluko ebangeni loMhlaba ukusuka eLangeni phakathi kwe-perihelion ne-aphelion ungamakhilomitha ayizigidi ezimbalwa. Nakuba lokhu kuzwakala kubalulekile, kungamaphesenti ambalwa kuphela ebanga elijwayelekile, ngakho-ke umphumela wawo emandleni elanga atholwa uMhlaba mncane uma kuqhathaniswa nezinye izici ezifana nokuthambekela kwe-axis yawo.
Ukuzihlukanisa kanye nezinkathi zonyaka eMhlabeni
Umbono ovamile oyiphutha ukuthi izinkathi zonyaka zenzeka ngoba uMhlaba useduze neLanga ehlobo futhi uqhelelene kakhulu ebusika. Eqinisweni, izinkathi zonyaka zinqunywa kakhulu ukuthambekela koMhlaba (cishe ama-23,5°), hhayi ukungavamile kwawo.
Ngokuthakazelisayo, uMhlaba empeleni useduze ne-perihelion cishe ekuqaleni kukaJanuwari, lapho iNyakatho yeNkabazwe ibhekana nobusika. Lokhu kusikisela ukuthi ibanga akuyona into eyinhloko enquma izinkathi zonyaka. Kodwa-ke, ukungafani kusenomphumela omncane: amandla okukhanya kwelanga ayahlukahluka kancane phakathi kwalapho uMhlaba use-perihelion kanye ne-aphelion. Lo mphumela ubonakala njengokwehluka okuncane ekusakazweni kwamandla elanga atholwa uMhlaba unyaka wonke.
Kungani ukungaziphathi ngendlela engavamile kungashintsha?
Ukungajwayelekile kwe-orbital akuhlali njalo. Ezinhlelweni ezinamaplanethi amaningi, ukudonsa kwamandla adonsela phansi phakathi kwamaplanethi kubangela ukuthi imijikelezo ishintshe kancane kancane. Ngezikhathi zezinkulungwane kuya kwezigidi zeminyaka, ukungazivumelani kwe-Earth kubhekana nokushintshashintsha okuyingxenye yemijikelezo yaseMilankovitch—uchungechunge lwezinguquko eziqhubekayo kumapharamitha okujikeleza kwe-Earth kanye nokujikeleza ahlobene namaphethini esimo sezulu sesikhathi eside, kufaka phakathi isikhathi seqhwa.
Ngaphezu kokuxhumana phakathi kwamaplanethi, ukusondela kwezinye izinto ezinkulu, ukuzwakala kwe-orbital, kanye nomlando wokwakheka kohlelo lwamaplanethi (isb., ukushayisana noma ukufuduka kwamaplanethi) nakho kungathinta ukungafani.
Ukuhlukahlukana kwamaplanethi angaphandle: kusukela ekuthuleni kuya kokubi kakhulu
Lapho izazi zezinkanyezi ziqala ukuthola amaplanethi angaphandle (amaplanethi angaphandle kwesimiso sethu sonozungezilanga), zathola ukuthi amaningi awo ayenobunye obukhulu kakhulu kunamaplanethi ethu. Amanye ama-gas giant azungeza eduze kakhulu nezinkanyezi zawo (“ama-hot Jupiter”) anemizila ecishe ibe yindilinga ngenxa yemiphumela yolwandle oluzinzisa imizila yawo, kodwa amanye amaplanethi amaningi angaphandle abonisa imizila ejikelezayo efana ne-elliptical.
Ukungajwayelekile okuphezulu kuvame ukusikisela umlando "onzima" oguquguqukayo, isibonelo:
- ukusebenzisana okunamandla kwamandla adonsela phansi phakathi kwamaplanethi,
– ukuphazamiseka okuvela ezinkanyezini ezihambisanayo ezinhlelweni zezinkanyezi ezimbili,
– noma ukushayisana nokukhishwa kwamaplanethi ngesikhathi sokwakheka kwasekuqaleni kwesistimu.
Imizila ejikelezayo ezungezile yenza nezimo zemvelo zeplanethi zibe zimbi kakhulu: izinguquko ebangeni lenkanyezi zibangela izinguquko ezinkulu ekushiseni kanye namandla emisebe etholakala phakathi nomjikelezo.
Umthelela wokungajwayelekile endaweni yokuhlala
Ekucwaningweni kokuhlalwa kweplanethi, ukungavamile kuyipharamitha ebalulekile. Uma iplanethi inokungafani okukhulu, kungaba:
– ichitha ingxenye yomjikelezo wayo iseduze kakhulu nenkanyezi (ishisa kakhulu),
– kanti abanye bakude kakhulu (kubanda kakhulu).
Kodwa-ke, ukukwazi ukuhlala akunqunywa nje kuphela yibanga. Isimo sezulu esijiyile, izilwandle, noma izindlela zokujikeleza kokushisa zingasiza ekuqiniseni amazinga okushisa. Kunezimo lapho amaplanethi anesimo esingavamile esimaphakathi angase abe nendawo ephumelelayo yokuhlala, ikakhulukazi uma isilinganiso samandla okungenisa sisekela amanzi acwebile futhi umoya ukwazi ukusabalalisa ukushisa.
Ngakolunye uhlangothi, izinto ezinkulu ezingavamile zinamandla okubangela ukushintshashintsha okukhulu kwesimo sezulu, zibhebhethekise ukungazinzi kwesimo sezulu, zishintshe amaphethini ezinkathi zonyaka, futhi zithinte ngisho nokusebenzisana kwamaza nenkanyezi, okungafudumeza ingaphakathi leplanethi (ukushisa kwamaza) noma kusheshise ukuvela kwayo kokujikeleza.
Ukulinganisa ukungavamile: izazi zezinkanyezi zazi kanjani?
Esimisweni sonozungezilanga, ukungafani kunqunywa ngokunembile kakhulu ngokubuka izikhundla zamaplanethi ngokuhamba kwesikhathi. Kumaplanethi angaphandle, izindlela ezivamile zifaka:
– Ijubane lemisebe: lilinganisa “ukuntengantenga” kwenkanyezi ngenxa yokudonswa yiplanethi; ukuma kwejika lesignali kungaveza ukungavamile.
– Ukuhamba: lapho iplanethi idlula phambi kwenkanyezi, ubude kanye nesimo sokuhamba, kanye neminye imininingwane, kunganikeza izinkomba ngesimo sokujikeleza.
– Ukwehluka kwesikhathi: izinguquko esikhathini sokuhamba (i-TTV) ngenxa yokusebenzisana kwamaplanethi kungasiza ekwembuleni imingcele ye-orbital kufaka phakathi ukungafani.
Uma siqoqa idatha eningi, kulapho silinganisa khona ukuthi izinto azifani nezinye futhi siqonda kangcono ukuguquguquka kwesistimu.
I-Penutup
Ukungajwayelekile komjikelezo weplanethi kuyisici esibalulekile sokuqonda ukuthi kungani imijikelezo ingabi yindilinga njalo, kungani ibanga leplanethi ukusuka enkanyezini yayo lishintsha, nokuthi kungani ijubane leplanethi lingaguquki kulo lonke umjikelezo wayo. Esimisweni sonozungezilanga, ukungajwayelekile kweplanethi kuncane kakhulu, okwenza i-orbital dynamics ibonakale "izolile." Kodwa-ke, amaplanethi amaningi abonisa imijikelezo engajwayelekile kakhulu, okwembula ukuthi ukuvela kwezinhlelo zamaplanethi kungaba yinkimbinkimbi kakhulu futhi kugcwele ukusebenzisana okumangalisayo.
Ngokuqonda ukungavamile, asigcini nje ngokufunda i-geometry yezindlela zokujikeleza, kodwa futhi sifunda "umlando" wamandla adonsela phansi owakha uhlelo lwamaplanethi—futhi sihlole ukuthi ukuma komzila kungathinta kanjani isimo sezulu kanye namathuba okuvela kwendawo enobungani nokuphila.
