Kalinanyanga iKhwezi
SIQHUBEKA lapho sigcine khona ngeledlule lapho besibheka ukwakheka kweKhwezi. Sikhulume ngokwakheka kobusomhlaba (surface) nengaphakathi lalo mhlaba iningi elicabanga ukuthi yinkanyezi - njengoba sike sasho phambilini.
Inkundlazibuthe ( magnetic
field) nethambo ( core) ngonyaka we-1967, isiphuphutheki ( spacecraft), uVerena 4, sithole ukuthi inkundlazibuthe yeKhwezi ithanda ukuba ntekenteke uma iqhathaniswa neyoMhlaba. Ithambo kucatshangelwa ukuthi “linogesi”.
Ukushisa kwethambo kuthiwa yikhona okufudumalisa ubusomhlaba. Kunokuhlawumbisela ukuthi (ithambo) lithanda ukuba wuketshezi noma kalipholile, okwenza kucatshangwe ukuthi amazinga okushisa kuyona yonke le ndawo esaluketsheni acishe afane.
Ukuba ntekenteke kukazibuthendilinga ( magnetosphere) ozungeze iKhwezi kusho ukuthi isajasivunguvungu ( solar wind) sixhumana ngqo nengaphandle lengubomkhathi ( atmosphere) yeKhwezi. IKhwezi lizungeza iLanga ebangeni elilinganiselwa e-108 million km (okungaba yi-0.7 Astronomical Units - AU), lithatha izinsuku ezingama-224.7 umzungezo ngamunye. Cishe umzungezo wayo yonke imihlaba ezungeza ilanga isaqanda ( elliptical), oweKhwezi-ke ucishe ube yindilinga nje impela.
Yonke imihlaba eyakhele iLanga ilizungeza iphambane nokuhamba kwewashi, iningi layo futhi liphenduka emzileni walo liphambane newashi kodwa iKhwezi lona liphenduka lihambisane newashi - kulokhu kuphenduka kwalo okuthatha izinsuku ezingama-243, okungeziningi kunazo zonke ezithathwa ngeminye imihlaba eyakhele iLanga uma iphenduka.
Ngenxa yokuzungeza kwalo ngesivinini sonwabu, iKhwezi licishe libe yindilinga ephelele. Inkabazwe yalo iphenduka ngesi-6.52 km/h kanti uMhlaba wona yi-1.669.8 km/h. Isivinini sokuphenduka kweKhwezi sehlile eminyakeni eli-16 kusukela ekuhlolweni kwalo yisiphuphutheki, iMagellan [esisuke emhlabeni ngoNhlaba (May) we-1989 - zili-10 kuNcwaba (August) we-1990] kuya kwiVenus Express [esuke emhlabeni ziyisi-9 kuLwezi (November) wezi-2005 yafika eKhwezini zili-11 kuMbasa (April) wezi-2006].
Unsukubhekenkangala ( sidereal day) - othatha ama-23h56.4 weKhwezi sewenyukile ngemizuzu eyisi-6.5. Kuvela ukuthi uma umuntu engabuka iLanga esebuswenimhlaba beKhwezi, angalibona li- phuma entshonalanga lishone empumalanga - yize-ke amafu ashubile alo mhlaba okwenza kube nzima ukuba ungabona iLanga usebuswenimhlaba bawo.
Njengezinye izakhiwomkhathi ( celestial bodies) ezakhele iLanga, iKhwezi kucatshangelwa ukuthi lakheke ngokubumbeka kwengxenye ethile yefuzelamani-lugqulu ( nebula) eyasala ngesikhathi kwakheka iLanga.
Ikhwezi kalinayo inyanga kodwa linenqwaba yezingamhlaba ( asteroids) ezibizwa ngamaTrojan, yisinganyanga ( quasi-satellite) u-2003 VE68 nama- trojan amabili angahlali isikhathi eside, i-2201 CK32 ne-2012 XE133. Ngekhulunyaka le-17, uGiovanni Cassini owayengusonkanyezi ( astronomer) waseItaly, wabika ukuthi kunenyanga ezungeza iKhwezi, eyayibizwa ngeNeith.
Ukubonakala kwale nyanga kwabuye kwabikwa kaningana eminyakeni engama-200 elandelile kodwa abaningi babethi kungenzeka kube yizinkanyezi eziseduze (kwesimonkanyezi seLanga).
Ucwaningo luka-Alex Alemi noDavid Stevenson beCalifornia Institute of Technology, e-United Stated of America (USA) lwangowezi-2006, mayelana nesimonkanyezi seLanga sisesisha, luveza ukuthi kungenzeka ukuba iKhwezi lake laba nenyanga eyayidalwe wukuhlaselwa kanzima kwalo yizingamhlaba eminyakeni eyizigidigidi eyedlule.
Eminyakeni elinganiselwa kweli-10 million emuva kokuhlaselwa yizingamhlaba, ngokwalolu cwaningo, iKhwezi laphinde lahlaselwa ngezinye izingamhlaba okwenza ukuba indlela inyanga yalo ishintshe indlela ephenduka ngayo. Kucatshangelwa ukuthi yaphaphatheka yaphendukela ngaphakathi okwaholela ekubeni ingqubuzane neKhwezi, kwaphela ngayo.
Sizoyiqhuba ngokulandelayo
UMZUNGEZO ( ORBIT) NOKUPHENDUKA ( ROTATION)