Selenological implications drawn from the distortions of craters in the Hipparchus region of the Moon
Abstract
Measurements of craters in the Hipparchus region of the Moon are used to show that the craters are distorted preferentially, their longer axes most frequently lying parallel to the most prominent family of the grid system. It is shown that the mean percentage distortions generally increase with the age of a crater, and that the larger craters are generally older than the smaller ones. Taken qualitatively, the present results may be used to confirm the conclusions which were reached earlier for the Vaporum region of the Moon; namely, that the compressive stresses which produced the observed distortions acted for a longer time on an old crater than on a young crater. The quantitative differences between the two sets of results may be explained readily in terms of the relative strengths of the two principal stress-systems which produced the grid system in these parts of the Moon. These two systems must have formed in the same era, rather than during separate eras. Finally, the results are used to isolate the most recently formed craters. The probability that these craters are distributed at random is found to be 0.7, so that it is not unlikely that they are of impact origin.
- Publication:
-
Planetary and Space Science
- Pub Date:
- January 1962
- DOI:
- 10.1016/0032-0633(62)90065-X
- Bibcode:
- 1962P&SS....9....3F