Úmhlâba (i-astronomy)
Úmhlâba yiplanethi yesitsatfu kusuka eLangeni futsi nguyona kuphela intfo leyinkhanyeti leyatiwa kutsi inekuphila. Loku kwenta uMhlaba waba ngumhlaba waselwandle, nguwona kuphela ku Solar System lophetse emanti ngetulu kwemanti. Cishe onkhe emanti eMhlaba akhona etilwandle tayo temhlaba wonkhe, letimbonya 70.8% wemhlabatsi. Le 29.2% lesele yemhlabatsi, liningi lawo lisesimeni se continental crust ngekhatsi kwemhlabatsi. Liningi lemhlaba lokungenani limanti futsi limbonywe ngeluhlata, kantsi emashidi lamakhulu e-ice etihlane teMhlaba te-Polar abamba emanti lamanyenti kunalamanti langaphansi kwemhlaba, emachibi, imifula kanye nemoya lokuhlanganisiwe. Luhlaka lweMhlaba lufaka emapuleti e-tectonic lahamba kancane, lashayisana kute akhicite tintsaba, tintsaba temlilo kanye nekutamatama kwemhlaba. Umhlaba unemgogodla wangaphandle loketshezi lokhicita i-magnetosphere lekhona kuphambukisa imimoya leminyenti yelanga lebhubhisako kanye nemisebe ye-cosmic.