Ukuthambekela kwe-Axis of Rotation yePlanethi
Ukuthambekela kwe-axis yokujikeleza kweplanethi—okuvame ukubizwa ngokuthi ukuthambekela kwe-axial noma ukufiphala—kungenye yezindlela ezibaluleke kakhulu ekunqumeni “ubuso” beplanethi. Kuthinta ubude bemini nobusuku, amaphethini esizini, ukusatshalaliswa kwamandla elanga ebusweni, ngisho nokuguquguquka kwesimo sezulu sesikhathi eside. Kuhlelo Lwelanga, iplanethi ngayinye inokuthambekela okuhlukile kwe-axial, kusukela cishe ku-perpendicular kuya kulezo ezibonakala “zigoba” futhi ziphenduka emizuliswaneni yazo. Ukuqonda ukuthambekela kwe-axis yokujikeleza akusisizi nje kuphela ukuchaza ukuthi kungani uMhlaba unezinkathi zonyaka, kodwa futhi kuvula ukuqonda ngomlando wokushayisana, ukwakheka kwamaplanethi, kanye nokuhlala kwamaplanethi kwezinye izinhlelo zezinkanyezi.
Kusho ukuthini ukuthambekela kwe-axis yokujikeleza?
I-axis of rotation ingumugqa ongokomfanekiso oxhumanisa izinsika ezisenyakatho neziseningizimu zeplanethi; iplanethi ijikeleza kulo mugqa. Ukuthambekela kwe-axis of rotation kuyi-engeli ephakathi kwe-axis of rotation yeplanethi kanye nomugqa oqondile endizeni yayo ezungeza ilanga (indiza ye-ecliptic yamaplanethi azungeza iLanga). Ukube i-axis of rotation ibiqonde phezulu ngokuphelele (i-tilt 0°), iplanethi ibingeke ibhekane nezinkathi ezibalulekile ngoba ukukhanya kwelanga bekuyohlala kuhambisana ne-equator unyaka wonke.
Umhlaba unokuthambekela okungaba ngu-23,5°. Lokhu kubangela ukuthi izingxenye ezisenyakatho neziseningizimu zithambekele eLangeni ngokushintshana kulo lonke umjikelezo wazo waminyaka yonke, okuholela ehlobo nasebusika.
Kubalulekile ukuqaphela ukuthi ukuthambekela kwe-axial kuhlukile ekungajwayelekile kwe-orbital (ukuthi umjikelezo weplanethi u-elliptical kangakanani). Izinkathi zingathonywa yizo zombili, kodwa eMhlabeni, izinkathi zinqunywa kakhulu ukuthambekela kwe-axial, hhayi ibanga phakathi koMhlaba neLanga.
Kungani ukuthambekela kwe-axis yokujikeleza kuveza izinkathi?
Cabanga ngoMhlaba uzungeza iLanga nge-axis yawo yokujikeleza ehlala iqondiswe endaweni efanayo esibhakabhakeni (ebheke ePolaris). Lapho ingxenye esenyakatho yezwe ithambekele eLangeni, iLanga libonakala liphezulu esibhakabhakeni emini, futhi izinsuku ziba zinde. Ngenxa yalokho, amandla elanga atholwa ngeyunithi ngayinye ayanda, izinga lokushisa elijwayelekile liyakhuphuka, futhi ihlobo liyenzeka enyakatho yezwe. Ngesikhathi esifanayo, ingxenye eseningizimu yezwe ithola ukukhanya okuthe slint kanye nezinsuku ezimfushane, okuholela ebusika.
Ngaphezu kwezinkathi zonyaka, ukuthambekela kwe-axial kuphinde kuthonye izimo ezimbi kakhulu ezindaweni eziphakeme, njengelanga eliphakathi kwamabili (ilanga alishoni ehlobo) kanye nobusuku obuphakathi nendawo (ilanga aliphumi ebusika). Uma ukuthambekela kwe-axial kukhulu, kulapho lokhu kuhlukahluka kukhulu khona.
Ukwehluka kokuthambekela ohlelweni lwelanga
Iplanethi ngayinye inomlando "wokwakheka kwayo ngokuthambekela kwayo kwe-axial. Nasi umbono jikelele ngamanye amaplanethi:
– I-Mercury: ukuthambekela kwayo kuncane kakhulu (kusondela ku-0°), ngakho-ke cishe azikho izinkathi zonyaka. Kodwa-ke, ngenxa yokuthi ayinawo umoya obalulekile, umehluko wokushisa unqunywa kakhulu yizinsuku zayo ezinde nobusuku.
– I-Venus: ihlukile ngoba ijikeleza kancane kakhulu futhi ijikeleza emuva (ngakolunye uhlangothi) ngokuthambekela okukhulu ngokwencazelo (cishe ngo-177° uma kubalwa njengokuthambekela emuva). Ngokwendlela engokoqobo, i-Venus “icishe ibheke phansi,” yize imiphumela yesizini incane ngoba umoya wayo ojiyile ulingana nokushisa.
– Umhlaba: 23,5° ukhiqiza izinkathi ezicacile kodwa ezingembi kakhulu, okuyisici esibalulekile sokuqina kwesimo sezulu.
– I-Mars: cishe ama-25°, afana noMhlaba, ngakho-ke i-Mars nayo inezinkathi zonyaka. Uma kuhambisana nokungajwayelekile kokujikeleza kwe-Mars, izinkathi ku-Mars zingahluka ngobukhulu phakathi kwezingxenye ezisenyakatho neziseningizimu.
– I-Jupiter: cishe ama-3°, izinkathi zonyaka azibonakali kahle; ukuguquguquka kwayo komoya kuthonywa kakhulu ukushisa kwangaphakathi kanye nokujikeleza okusheshayo.
– I-Saturn: cishe ngama-26–27°, inkulu impela futhi ibangela ukushintshashintsha kwesizini emkhathini nasemasongweni, yize isikhathi sesizini side ngoba i-Saturn ithatha cishe iminyaka engama-29,5 ukuzungeza iLanga.
– I-Uranus: cishe ama-98°, kubonakala sengathi “ilele” endizeni yayo ezungezayo. Ngenxa yalokho, ingxenye enkulu yonyaka we-Uranus, isigxobo esisodwa singabhekana neLanga njalo. Izinkathi zaso zonyaka zimbi kakhulu futhi zihlala isikhathi eside (i-Uranus izungeza iLanga eminyakeni engama-84).
– I-Neptune: cishe ama-28–30°, inezinkathi zonyaka kodwa ziyashintsha kancane ngenxa yesikhathi sayo sokuzungeza esingama-~165 eminyaka.
Lokhu kuhlukahluka kubonisa ukuthi ukuthambekela kwe-axial akuyona nje "imininingwane emincane," kodwa kunalokho kuyisici esinqumayo sobuntu beplanethi.
Yini enquma ukuthambekela kweplanethi?
Ukuthambekela kwe-axis yokujikeleza kuthonywa yizici eziningi, ikakhulukazi ngesikhathi sokuqala kokwakheka kwesistimu yamaplanethi:
1. Imithelela emikhulu
Ngesikhathi sokwakheka kwawo, amaplanethi angqubuzana nama-protoplanethi noma ezinye izidalwa ezinkulu. Ukungqubuzana okunjalo kungashintsha kakhulu indlela yokujikeleza kwawo kanye nokuthambekela kwawo kwe-axial. I-giant impact hypothesis ivame ukuhlotshaniswa nokwakheka kweNyanga kanye nokuthambekela koMhlaba.
2. Ukusebenzisana kwamandla adonsela phansi okude
Ukuphazamiseka kwamandla adonsela phansi okuvela kwamanye amaplanethi kungashintsha kancane kancane indlela okuqondiswa ngayo i-axis kanye ne-orbit. Amandla okuzwana angabangela ukuthambekela kwe-axis kushintshe ngokuhamba kwesikhathi.
3. Ukusatshalaliswa kwesisindo sangaphakathi
Uma iplanethi inokuqhuma kwe-equatorial (ngenxa yokujikeleza), noma ukusatshalaliswa kobuningi obungalingani, amandla adonsela phansi eLanga namanye amaplanethi angabangela ukunyakaza kwe-precession (ukunyakaza "okuphezulu") ku-axis yokujikeleza.
4. Ithonya lamasathelayithi amakhulu
INyanga idlala indima ebalulekile ekuqiniseni ukuthambekela koMhlaba. Ngaphandle kweNyanga, amanye amamodeli aphakamisa ukuthi ukuthambekela koMhlaba kungashintshashintsha kakhulu futhi ngendlela exakile ngokwezikhathi ze-geologic, okungase kuholele ezimweni zezulu ezimbi kakhulu.
Ukuguquka kanye noshintsho ekuthambekeleni: ukuthambekela akuhlali njalo
I-axis yokujikeleza kweplanethi ivame ukudlula, ushintsho oluhamba kancane kancane ohlangothini lwe-axis yayo, njengesihloko esijikelezayo. Umhlaba udlula esikhathini esicishe sibe yiminyaka engu-26.000. Ngaphezu kwalokho, ukuthambekela koMhlaba nakho kuyashintsha kancane—kusukela cishe ku-22,1° kuya ku-24,5°—ngesikhathi esicishe sibe yiminyaka engu-41.000. Kanye nokunye ukushintshashintsha kwe-orbital, lezi zinguquko ziyingxenye yemijikelezo yaseMilankovitch, ehlotshaniswa namaphethini enkathi yeqhwa kanye noshintsho lwesimo sezulu lwesikhathi eside.
Kwamanye amaplanethi, ukushintshashintsha kokuthambekela kungaba kukhulu kakhulu. Isibonelo, iMars kucatshangwa ukuthi ibhekane nezinguquko zokuthambekela okukhulu emlandweni wayo, okwakungathinta ukuzinza kwezingqimba zeqhwa zayo ezibandayo kanye nokuba khona kwamanzi angcolile esikhathini esidlule.
Umthelela wokuthambekela kwe-axial esimweni sezulu kanye nokuhlala endaweni ethile
Ukuthambekela kwe-Axial kuthinta ukuhlala kwamaplanethi ngezindlela eziningana:
– Ukusatshalaliswa kwamandla: Ukuthambekela okulingene kusiza ukusabalalisa amandla eLanga ezindaweni eziphakeme ehlobo, kuvimbele izinsika ukuthi zingabanda kakhulu unyaka wonke.
– Izinkathi eziyingozi kakhulu: Ukuthambekela okukhulu kakhulu kungadala izinkathi eziyingozi kakhulu—ihlobo elishisayo kakhulu kanye nobusika obubandayo kakhulu—okuyinselele ekuzinzeni kwe-biosphere, umkhathi kanye nolwandle.
– Ukuzinza kwesikhathi eside: Ukushintshashintsha kokuthambekela okuxakile kungenza kube nzima ngesimo sezulu ukuthi sihlale sizinzile eminyakeni eyizigidi, okungase kuphazamise ukuvela kwempilo eyinkimbinkimbi.
Kodwa-ke, "ukuthambekela okuhle" akuyona into eyodwa. Amaplanethi anezimo ezijiyile, izilwandle ezinkulu, noma ukujikeleza kokushisa okuphumelelayo angamelana kangcono nezimo ezimbi kakhulu. Ngisho nokuthambekela okukhulu akwenzi ngokuzenzakalelayo iplanethi ingahlalwa muntu; kumane kushintsha uhlobo lwezinselele zesimo sezulu ebhekene nazo.
Ukuthambekela kwe-Axial kanye nokusesha amaplanethi afana noMhlaba
Ezifundweni ze-exoplanet, ukuthambekela kwe-axis ye-exoplanet kunzima kakhulu ukukulinganisa ngqo, kodwa ososayensi bangaphetha izinkomba ezivela ekuhlukeni kokukhanya kweplanethi, amaphethini ezinkathi emkhathini wayo (kumaplanethi anokubuka okuningiliziwe), noma amamodeli okuguquguquka kwesistimu. Uma ngelinye ilanga singalinganisa ukuthambekela kwe-axis ye-exoplanet ngokunembe kakhudlwana, lolo lwazi lungasiza ekuhloleni ukuthi iplanethi ingaba nezinkathi ezizinzile, isimo sezulu esibi kakhulu, kanye nendawo evumela amanzi ahlanzekile.
I-Penutup
Ukuthambekela kwe-axis yokujikeleza kweplanethi kuyisihluthulelo sokuqonda izinkathi zomhlaba, isimo sezulu, kanye nomlando. Kusukela eMhlabeni, othambekele ku-23,5° futhi onezinkathi ezithambile, kuya ku-Uranus, "owela phansi" futhi obhekana nezinkathi ezimbi kakhulu amashumi eminyaka, ukuthambekela kwe-axial kwembula ukuhlukahluka kwezimo zamaplanethi. Kubunjwe umlando omude wokushayisana kanye nokudonsa kwamandla adonsela phansi, futhi kushintsha njalo ngokusebenzisa i-precession kanye nokusebenzisana okunamandla. Ngokubanzi, ukufunda ukuthambekela kwe-axial akukhona nje kuphela nge-geometry; kumayelana nokuhlola izici ezingenza iplanethi ibe yindawo ejabulisayo ukuba kuyo—noma, ngokuphambene nalokho, umhlaba onesimo sezulu esingalindelekile.
Uma ufisa, ngingangeza ithebula lokuthambekela kwe-axis yokujikeleza kweplanethi ngayinye kanye nemiphumela yayo yesizini, noma ngidale inguqulo yesayensi kakhulu yalesi sihloko enezinkomba kanye nezibalo eziyisisekelo zokushiswa kokukhanya (ubukhulu bomsebe welanga).
