lighting will do it, make sure with scene selected in the outliner the ambient is set to zero

you probably want to use distant light (not sunlight and the sky or realistic sky options)

the crescent shape will come down to your camera angle in relation to sphere primitive I assume you will use

that said Carrara does include pre-sets for Earth and other planets

also

https://www.daz3d.com/forums/categories/carrara-discussion

will get you more help than on this forum as not many Carrara users frequent it