Influence of the lunar ambience on dynamic surface hydration on sunlit regions of the Moon

The accepted paradigm of a dry Moon has been upset by the recent detection of a wet Moon. EPOXI, NASA's extended mission for the Deep Impact spacecraft, observed and quantified dynamic surface hydration on sunlit regions of the Moon by infrared spectrometry in separate flybys. MIP CHACE, released from ISRO's Chandrayaan-1 spacecraft, detected H2O by mass spectrometry in orbit in the sunlit lunar ambience at a partial pressure exceeding Apollo inferences by over two orders of magnitude. Here it is shown CHACE and EPOXI are mutually supportive, suggesting the order of magnitude reported by CHACE is correct. With this confirmation in mind, it is shown the CHACE data imply H2O in the lunar ambience impinges upon near equatorial surfaces at an annual average of ∼400 g m−2 yr−1 by cursory estimate.