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Scientists Find Direct Evidence of Ice On the Moon (qz.com)
According to a new study, published today in the Proceedings of the National Academy of Sciences, scientists have found the first direct evidence of frozen water on the Moon's poles. "The discovery is based on data gathered by the Moon Mineralogy Mapper, a NASA instrument that flew to the Moon back in 2008," reports Quartz. From the report: Reanalyzing this data today, the researchers found tiny patches of ice mixed with rock on the surface of certain craters at the northernmost and southernmost points on the Moon. Shuai Li, a geologist at the University of Hawaii who worked on the study, says the data can't tell us where the ice originally came from. However, Li adds, it's likely that it came from comets that smashed into the Moon years ago. Collisions with other space objects, like meteorites and comets, gave the Moon its pockmarked surface, and could have easily brought a foreign substance like ice along with them. Ice on the lunar surface could also be a result of gases coming out of the rock below. It could also be due to solar winds -- energetically charged ions emanating from the sun -- bombarding the Moon's surface to cause the chemical reactions needed to make frozen water. However, to truly understand the ice's origins, Li hopes to get a rover onto the Moon to take actual samples of the frigid lunar ground and its ice.
Ice on the lunar surface ... could also be due to solar winds -- energetically charged ions emanating from the sun -- bombarding the Moon's surface to cause the chemical reactions needed to make frozen water.
Oh, RIGHT!
Rocks are generally metallic oxides. Solar winds are mostly high-energy protons - hydrogen nuclei. Hit a rock molecule with one, hang a hydrogen off one of the oxygen nuclei, turning it into a hydroxyl group. Hit the hydroxyl again and you knock off. It grabs that or another nearby proton and now you've got a water molecule in a near-moon orbit that intresects its surface.
A lot of 'em are pointed away - and have more than escape velocity. Bye-bye. Others bounce away (at more than escape velocity) before they get slowed down by one or more collisions with surface features (to below escape velocity). But some end up losing enough momentum to hang around and eventually condense out on a cryogenically-cold shadowed side of a rock or crater wall. Frost!
One of those things that are obvious in hindsight.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way