Bringing rocks back from Mars

THE IDEA, popular in science fiction, that alien life will do bad things to life on Earth if the two come into contact, is not restricted to the activities of malevolent extraterrestrial intelligences. In “The Andromeda Strain”, a novel by Michael Crichton, the baddies are mysterious and deadly (but completely unintelligent) microbes that hitch a ride to Earth on board a military satellite. They start by killing everyone in the town of Piedmont, Arizona, and then wreak havoc in a secret underground government laboratory, as scientists struggle to understand and contain them.Move one state north, to Utah, and at least part of that fiction may, some hope, soon become true. For Utah is the planned landing place of the first samples to be collected from the surface of Mars. Optimists like to think that those samples might contain traces, even if only fossil, of life on Mars. And in case they do, the samples’ ultimate destination will be a purpose-built receiving facility with level-four biosafety controls—the highest category possible.