Ihlabathi

Ihlabathi yindawo eyiplanethi yesithathu ukusuka elangeni kwaye kukuphela kweplanethi eyaziwa njengenobomikuyo. Ihlabathi eli leenzeka kwisithuba sezigidigidi ezi4.5 billion zeminyaka eyadlulayo. lelinye leeplanethi ezine ezinamatye ngaphakathi kwisolar izinto ezijikeleze ilanga. Ezinye zazo ziiMercury, iVenus, kunye neMars.

Ubunzima obukhulu mass belanga benza okokuba ihlabathi lilijikeleze ngokwesazinge, kanye oku kobunzima behlabathi xa busenza okokuba inyanga ilijikeleze . Nehlabathi ngokunjalo liyazijikikelezela,  ngoko ke iindawo ngeendawo zijonge ngaselangeni ngamaxesha ahlukeneyo. Ihlabathi lijikeleza ilanga kanye (kube kanye ngo"year") qho kwisithuba esingangamawaka ama-365¼ lijikeleza oko (kanye ngo"suku").

Inyanga ijikeleza umhlaba qho kwiintsuku ezimalunga nama-27⅓, kwaye ibanokukhanya okuvela elangeni. Njengokuba ihlabathi lijikelelza ilanga kwangelo xesha linye, ukutshintsha kokukhanya kwenyanga kuthatha iintsuku ezimalunga nama-29½ ukuba itshintshe ebumnyameni iye ekukhanyeni okuqaqambileyo isuke apho iphindele ebumnyameni kwakhona. Kulapho ke kwavela khona lo mbono wenyanga.    Kodwa ke ngoku iinyanga ezininzi zineentsuku ezingama-30 okanye ama-31 zitsho zikulungele ukwenza unyaka.

ihlabathi kukuphela kweplanethi kwinkqubo yethu yezinto ezijikeleza ilanga enobumanzi obuninzi naamanzi. Malunga nama71% zomhlaba zogqunywe ngeelwandle. Ngenxa yesi sizathu, maxa wambi kuthiwa yiplanethi eluhlaza okwesibhakabhaka.  

Ngenxa yamanzi ayo, ihlabathi lilikhaya lezigidi zeentlobo zeizityalo nezilwanyana. Izinto eziphila emHlabeni ziyitshinsthe kwaphela umphezulu nembonakalo yomhlaba. umzekelo, cyanobacteria ekuqaleni watshintsha umoya kwaye wayinika I-oksijini. Indawo ephilayo kumphezulu woMhlaba ibizwa ngokuba yi "biosphere".

Igophe lokujika

Ihlabathi ngokubanzi  kude le kwilanga (lo mgama ubizwa ngokuba yi"Astronomical Unit"). Umhlaba uhamba ngendlela yawo ngesantya esikumyinge wama  ngomzuzwana.  Umhlaba ujika kuyo yonke le ndlela malunga ne-365¼ yamathuba athatyathwa lilanga ngelo xesha ke uMhlaba wona uchitha uyihamba yonke loo ndlela ujikeleza ilanga. Ukuze kubekho usuku olude kunezinye qho ngonyaka, usuku olongezelelweyo lubakho qho kwiminyaka emine. kuthiwe ke lo nyaka yi"leap year".

Inyanga ijikeleza umHlaba kumgama ongumyinge we . It is locked to Earth, so that it always has the same half facing the Earth; the other half is called the "Dark Side of the Moon". Kuthatha malunga neentsuku ezingama-27⅓ ukuba iNyanga ijikeleze umhlaba wonke kodwa, ngenxa yokuba uMhlaba ujikeleza iLanga ngaxeshanye, kuthatha malunga neentsuku ezingama-29½ ukuba iNyanga isuke ebumnyameni iye ebumnyameni iye ebumnyameni kwakhona. Kulapho igama elithi "inyanga" lavela khona, nangona iinyanga ezininzi ngoku zineentsuku ezingama-30 okanye ezingama-31

Imithombo