Key points are not available for this paper at this time.
The idea that ice and other trapped volatiles exist in permanently shadowed regions near the lunar poles was proposed by Watson, Murray, and Brown 1961. It is reexamined in the present paper, in the light of the vast increase of our lunar knowledge. The stability of the traps and the trapping mechanism are verified. Four potential sources of lunar H 2 O, (1) solar wind reduction of Fe in the regolith, (2) H 2 O‐containing meteoroids, (3) cometary impact, and (4) (the least certain) degassing of the interior, can supply amounts of trapped H 2 O estimated in the range of 10 16 –10 17 g. Two important destructive mechanisms have been identified: photodissociation of H 2 O molecules adsorbed on the sunlit surface and sputtering or decomposition of trapped H 2 O by solar wind particles. The effect of impact gardening is mainly protective. The question of the presence of H 2 O in the traps remains open; it can be settled by experiment.
J. R. Arnold (Mon,) studied this question.