NASA’s InSight Mars lander touches down Nov. 26, part of a careful robotic approach to exploring the red planet. But human exploration of Mars will inevitably introduce Earth life. Are you OK with that?
When NASA first started planning the Kepler mission, no one knew if the universe held any planets outside our solar system. Thousands of exoplanets later, the search enters a new phase as Kepler retires.
Planetary protection protocols try to make sure we don’t seed places like Mars with life from our planet. An astrobiologist argues they’re misguided – especially with human astronauts on the horizon.
Artist’s impression of Proxima Centauri b.
ESO/M. Kornmesser