- "Yes, we know there are local concentrations of REE on the moon," Pieters told SPACE.com, referring to rare earth elements by their acronym REE.
- KREEP is an acronym based on element symbols for the geochemical component in lunar rocks rich in potassium (K), rare-earth elements (REE), phosphorus (P), thorium, and other incompatible elements, Gertsch explained.
- KREEP is exposed on the lunar surface in certain areas, Gertsch said. Although rare earth elements are not themselves presently detectable by remote instruments, spotting thorium sharpens the ability to spot associated rare-earth elements on the moon's surface due to similar geochemical properties that caused them to crystallize under the same conditions, she added.
- "For rare earths, they are called rare for their low abundance, not economic value. However, some do have practical use in manufacturing, as in superconducting magnets," said Paul Spudis, a planetary scientist and leading advocate for exploring the moon at the Lunar and Planetary Institute in Houston.
- "The only possible use of such I have heard of is the possibility of mining lunar thorium not a rare earth, strictly speaking, but associated with them to fuel nuclear reactors for power generation at a lunar base. Quite a distant prospect, I suspect," Spudis advised.
- For Spudis, the real strategic lunar commodity is water.
If all we want from the moon is water, we may as well not go.