Ihlabathi jikelele

Umhlaba (igama lesiNgesi: uMhlaba) yiplanethi yesithathu evela ngaphakathi nangaphandle kwenkqubo yelanga. Ikwangoyena mhlaba usemhlabeni kwinkqubo yelanga ngokobubanzi, ubunzima, kunye noxinano. Imalunga neekhilomitha ezizigidi ezili-149.6 (iyunithi enye yeenkwenkwezi) ukusuka elangeni. Umhlaba ujikeleza usuka entshona uye empuma ngelixa ujikeleza ilanga. Okwangoku iminyaka engama-4.55 ezigidi zeminyaka ubudala, umhlaba unesathelayithi yendalo-inyanga, kwaye ezi zimbini zenza inkqubo yesibhakabhaka-inkqubo yenyanga-yomhlaba. Ivela kwilanga lokuqala le-nebula ye-4.55 yezigidigidi zeminyaka eyadlulayo.
I-radiator yomhlaba yi-6378.137 yeekhilomitha, irediyasi ye-polar ziikhilomitha ezingama-6356.752, umndilili ophakathi umalunga neekhilomitha ezingama-6371, kwaye umjikelo wekhweyitha umalunga neekhilomitha ezingama-40075. I-ellipsoid engavumelekanga enezibonda ezicwangcisiweyo kunye ne-equator encinci. Umhlaba unendawo engaphezulu ye-510 yezigidi zeekhilomitha, apho i-71% yolwandle kunye ne-29% ngumhlaba. Xa ujongwa emajukujukwini, umhlaba ngokubanzi uluhlaza okwesibhakabhaka. Umoya ojikeleze umhlaba ubunjwe yi-nitrogen kunye neoksijini, kunye nenani elincinci lekhabhon diokside kunye neArgon.
Ingaphakathi lomhlaba lahlulwe laba sisiseko, ingubo, kunye nolwakhiwo lweqweqwe, kwaye kukho ihydrosphere, iatmosfera kunye nemagnethi yomhlaba ngaphandle komhlaba. Umhlaba kuphela komzimba wasezulwini owaziwayo kwindalo yonke, kwaye ulikhaya lezigidi zezinto eziphilayo kubandakanya abantu.