Heres my latest artwork "Mankind Ambitions", before i made this artworks i just playing around with material exploration and end up making a whole scene lol.
I found the planet texture from free3d.com, i use two layers of geometry to make earth and mars like having a sky layer (with opacity).
whole scene takes 275samples, but the mars take 2000 samples with region render to achive less noise (caused by opacity velvet material)
check out my other artwork at IG : @ayyas.muh