Elon Musk wants to send humans to the red planet. But even our robotic presence there risks contaminating Mars with invasive microbes.
Twenty years ago, America celebrated its Independence Day by landing several thousand invaders on the surface of Mars.
All spacecraft components are limited to no more than 500,000 bacterial spores—about one-tenth as many as there are in a typical teaspoon of seawater.
If we keep our filthy meatbag bodies in space and teleoperate sterile robots on the surface, we’ll avoid irreversible contamination of Mars.