Mariner IV Photography of Mars: Initial Results

Abstract

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.