It is a scenario that may seem sci-fi, but it could happen.
NASA’s Mars Exploration Program Analysis Group this month issued a report on research needed to certify the safety of such a Mars mission.
One of the panel’s top priorities goes well beyond the scope of any mission in NASA’s current plans. The panel concluded that no amount of robotic testing on Mars could rule out the possibility of living microbial life at future human landing sites.
So astronauts could inadvertently bring the life back to Earth, with potentially dangerous consequences. “The possibility of transporting a replicating life form to Earth, where it is found to have a negative effect on some aspect of Earth’s ecosystem” would present the greatest biological risk, the team wrote.