Science. 1969 Apr 18;164(3877):297-9. doi: 10.1126/science.164.3877.297-a.
Comparisons of the various crater counts obtained from the Mariner IV photographs indicate that, out of 300 to 600 possible craters mapped by different investigators, only about 120 craters can be reliably identified. Thus, only a lower limit for the Martian crater density can be established from the Mariner IV data.
对从“水手四号”照片中获得的各种陨石坑计数的比较表明，在不同调查员所测绘的 300 到 600 个可能的陨石坑中，只有约 120 个陨石坑可以被可靠地识别。因此，只能根据“水手四号”的数据确定火星陨石坑密度的下限。
