mars's ground ~ at times it even snows, martian snowflakes are made of carbon dioxide rather than water & thought to be about the size of red blood cells, atmosphere is too thin to easily support life as we know it + is too cold for liquid water to exist for any length of time, dust that covers the surface is fine like talcum powder, beneath that layer of dust, the martian crust consists mostly of volcanic basalt rock, the centre likely has a solid core composed of iron, nickel, sulfur.
If I am exporting my files as high resolution for print, I change a few things. I rename to High res instead of gallery, I leave the resize to fit box UNCHECKED so my file will stay at the original size and I change the resolution to 300 instead of 72. I do not export sharpen for print. Some people do and if you choose you can select sharpen for matte or glossy paper. I then hit EXPORT and this will make me another file named High res with my files ready to burn to a disc or upload to ROES.
Face on Mars -- Cydonia The book gave this example of how our mind likes to see faces. A low resolution picture of MArs made people believe that life existed on that planet when in fact, a high resolution picture showed it was just a face-shaped rock.