The Science in the Fiction: Thomas Zega on Planetary Protection in the OSIRIS-REx Mission

NASA's recent OSIRIS-REx mission has returned a sample of asteroid Bennu all the way to Earth for detailed analysis. It is difficult to ignore the tempting similarities of this mission to the plot of Michael Crichton's 'The Andromeda Strain' and its sequel, Daniel H. Wilson's 'The Andromeda Evolution' - so in this episode Marty discusses Planetary Protection with Thomas Zega, a planetary scientist at the University of Arizona : what considerations and safeguards are in place to not only protect the sample from contamination by Earth, but Earth from contamination by the sample? We discuss the threat classification system employed by NASA when bringing astro-materials to earth, along with the inhospitable nature of the interplanetary environment to life as we know it, and the lines of evidence that should reassure us that we will not be wiped out by an unknown space pandemic. We also talk about tardigrades, panspermia, space-borne precursors to life, as well as the composition and minerology of asteroids and what they tell us about the evolution and structure of our solar system.