This composite of three artists' renderings from 1975 was only wish fulfillment for an unnamed JPL artist; however, the landscape and the rendered shapes took into account what was known about Mars that year. Compared to Earth, Mars is further away from the light of the sun, very cold and very arid, and had a thin atmosphere rich in carbon dioxide but little nitrogen, an environment distinctly inhospitable to complex, Earth-like, carbon-based life forms.
