ИСТИНА

In regions located at moderate and high latitudes > 45°, the maximal OHIBD is observed in the early morning around 06:00-08:00 local time. Already within the next 1-2 lunar hours the OHIBD decreases and reaches its minimum value around midday. Typically, the minimum OHIBD value amounts to less than 50% of the maximum value. In the afternoon, the OHIBD tends to increase again, but due to the sparseness of the available M³ data acquired under local afternoon conditions there is no clear evidence for the typical OHIBD level reached in the even-ing. A mechanism that might explain this behavior is the adsorption of solar wind protons reacting with oxygen atoms in the lunar surface minerals, counteracted by diffusion and photolysis of the formed OH/water. We observe also in regions located near the equator at low latitudes < 20° a significant OHIBD level. In this latitude range the OHIBD shows only insignificant variations with local time, where the OHIBD level is not far below the level observed at high latitudes. Our observation that the OHIBD level never drops down to zero independent of the latitude suggests the presence of a spectrally detectable strongly bounded water/OH component, which might add up with the variable, daytime-dependent component to generate the observed OHIBD behavior.