It’s human nature to clean for company more thoroughly than one would for oneself, but nowhere is this truth taken to greater extremes than at the Johnson Space Center. NASA’s setting new standards of cleanliness in its labs that handle samples returning from space. And their efforts are laying the groundwork for samples that might some day contain evidence of extraterrestrial life from Mars, Europa, and other points little known. Welcome to the Advanced Curation Laboratory, where the guests could entirely change our view of the Solar System.