The lunar surface may contain liquid water resources. Image: Torsten Edelmann, Wikipedia.
Reading aloud There is probably more water on the moon than expected? not only at the poles and in deep craters, but on the entire surface. The data from three space probes point to this: the Indian satellite Chandrayaan-1, which has been orbiting the moon since the end of 2008, the Saturn probe Cassini and the Nasa-operated comet mission Deep Impact. All three probes registered signals in sunlight reflected from the lunar surface, which clearly indicate the existence of chemical compounds between oxygen and hydrogen in the rocks of the surface. Most likely it is that these compounds are actually water, which is constantly re-formed by an interaction of the solar wind with the lunar rock. Already the Apollo missions should clarify the question whether the moon rock contains water. At that time, however, a clear answer could not be formulated: the containers containing samples of the lunar rock had become leaky, so that the traces of water contained therein were attributed to a contamination of the samples on earth. This assumption was supported by the fact that in the moonstones none of the chemical changes that are normally associated with the presence of water could be detected. Later, researchers came across evidence of water in the rock deep inside the moon. However, the question of the water on the surface remained unanswered.

The prevailing conjecture was that if there is water on the surface, then it is probably in the form of ice near the poles and deep craters in the interior, into which the sun does not penetrate. The new data suggest, however, that in addition there could be an extremely thin film of water on the entire surface. Although the probes also found stronger oxygen-hydrogen signals near the poles and in fresh craters, other areas also had measurable signal strengths. Initial projections by one of the teams suggest that in some regions, the amount of water could be up to half a percent by weight of the rock? provided that the signals actually come from water and not from so-called hydroxyl radicals, extremely reactive particles of a hydrogen and an oxygen atom.

The source of hydrogen-oxygen compounds could be the impact of comets or other bodies of water on the lunar surface. However, researchers find it much more likely that the water or hydroxyl is constantly being replicated on the surface? presumably when positively charged hydrogen ions from the solar wind react with the oxygen on the lunar rock. The resulting compound then appears to migrate towards the colder poles and accumulate there.

Carle Pieters (Brown University, Providence) et al .: Science, Online Preliminary Publications, doi: 10.1126 / science.1178658 Roger Clark (US Geological Survey): Science, Online Preliminary Publications, doi: 10.1126 / science.1178105 Jessica M. Sunshine (University of Maryland, College Park) et al .: Science, Online Pre-Publications, doi: 10.1126 / science.1179788 ddp / - Ilka Lehnen-Beyel advertisement


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