This is the authors' abstract. We don't add key points for this paper.
The 22 photographs of Mars taken by Mariner IV have been successfully received on earth. The Martian surface photographed is rather densely populated with impact craters whose sizes range up to at least 120 kilometers in diameter. We infer that the visible Martian surface is extremely old and that neither a dense atmosphere nor oceans have been present on the planet since the cratered surface was formed.
No takes yet. Share an insight, caveat, or question.
Leighton et al. (1965) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: