You're probably already hip to the fact that rare earth elements (REEs) are essential to many high-tech and clean energy technologies. Praseodymium, dysprosium, and ytterbium may not exactly roll off the tongue but you've probably got some of these "exotic" elements in your pocket and in the screen in front of you. They're not as rare as their name implies, but they are expensive - and environmentally "dirty" - to obtain.
REEs are found in local concentrations on the moon and asteroids. NASA notes that their Moon Mineralogy Mapper (M3) carried on India’s Chandrayaan-1 lunar-orbiting spacecraft in 2008-09 found several previously unknown new range of processes for mineral concentrations on the moon. Carle Pieters from the NASA Lunar Science Institute says that geologists have a good idea how lunar rare earth elements became concentrated (areas and outcrops where REEs are found are local and small), we need more surveys to map and characterize their distribution.
Given their apparent indispensability and the fact that they're politically and environmentally fraught, I think that sooner or later extraterrestrial mining for REEs is going to become not only economically viable, but politically critical and environmentally desirable. Europium, tantalum, and neodymium will become a lot more common words in our vocabulary in the future.
NerdGraph has created a nice little infographic giving some basic background on REEs. A small clip is above, but the full infographic is well worth a look - after the jump.