Prime Directive: How NASA's Planetary Protection Officer Keeps Our Germs from Contaminating Other Planets (& Vice Versa)
On July 20, 1969, humans set foot on the moon for the first time. But some say our microbes beat us there. With the Space Age came new questions about microscopic invaders from outer space and concern about where we are leaving our microbial footprints. The questions are even more relevant today.
