@wormspeaker

The sizes of the planets are their actual physical size, relative to each other. I kinda had to limit the sizes of the planets, because it wouldn't be practical to depict Earth and, say, Jupiter (either Earth is 1x1 pixel or Jupiter takes up 90% of the map). But since all the planets are terrestrial (humans can, in theory, land on all the depicted planets), their size is relatively close to Earths.