Big discovery. A few doors down at The Universe Today there is a report of findings showing that the moon is quite dry. This result is from an interpretation of radar soundings taken by the Japanese lunar probe SELENE.

Given the near proximity of the sun, and lack of any atmosphere, it would be astonishing that any water would be found on the moon, at least in the top few meters. Perhaps there are mineral hydrates in the regolith, but discrete surface water as ice or liquid in the shadows seems a bit of a stretch. Supposedly a trace of water was found by others near the polar regions where the sun angle is always low. 

Comets famously de-gas when they come near the sun. Maybe the moon was blowing a vapor trail too- 3 or 4 billion years ago.

The SELENE radar soundings were used to infer the presence of aqueous reservoirs well below the surface. The results failed to give any evidence of such bodies of water. Given the tumultuous history of the moon, as evidenced by the lava plains and impact activity it has experienced, there has been lots of opportunity for water to sublimate or cook off through fractures in the regolith in the past.

I like and appreciate the Universe Today site. But if I could offer some constructive criticism, they could do with more links to primary references rather than just recursive links to previous Universe Today articles. Actually, more than a few news sites do this.

On a side note, it is worth browsing the Japanese Space Agency (JAXA) website to get a feel for the depth of their program.

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