Analysis of lunar soil samples retrieved in 2020 during China's robotic Chang'e-5 mission has led to the discovery of a new and renewable source of water on the moon. The water inside tiny glass beads was formed during violent impacts from space rocks on the lunar surface, as reported by Reuters.
Scientists said that the spheres of glass were made of rocks that melted and cooled and contained water molecules formed due to action of the solar wind on the moon's surface. The solar wind is made of charged particles, primarily protons and electrons, spreading outward from the corona, the outermost part of the sun's atmosphere.
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The beads range in size from the width of one hair to several hairs; the water content was just a minuscule fraction of that, said Hejiu Hui of Nanjing University, who took part in the study, according to an AP report.
"The moon is constantly bombarded with impactors - for example micrometeoroids and large meteoroids - which produce impact glass beads during high-energy flash-heating events," planetary scientist Sen Hu of the Chinese Academy of Sciences' Institute of Geology and Geophysics, a co-author of study published in the journal Nature Geoscience, told Reuters.
Solar wind-derived water is produced by the reaction of solar hydrogen with oxygen present at the surface of the lunar glass beads, Hu explained. These spheres then act like a sponge for the water. As water is important for the sustainable exploration of planets, this discovery could be very useful for future explorers to produce and store it in missions.
About 1.7 kg of soil collected in the Chang'e-5 mission comprising 32 glass beads of about tens to hundreds of micrometres wide were examined in this research. The glass beads were found to hold water content of up to about 2,000 parts per million by weight, Hu told Reuters.
US space agency Nasa aims to send astronauts back to the moon by the end of 2025 and this time they will aim to explore the south pole where permanently shadowed craters are believed to be packed with frozen water, according to AP.
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