"The existence of resilient fungi may mean Earth microbes have already been introduced on Mars by previous rover missions."
Surviving the Sterilization
NASA has identified fungal strains that survive its most stringent sterilization procedures. This discovery raises concerns about potential contamination of Mars and other celestial bodies with Earth microbes.
The fungal strains persisted through NASA's standard sterilization protocols. Future Mars rover missions may face increased difficulty in preventing biological contamination.
A History of Unsterilized Probes
Past missions, including the Cassini-Huygens probe to Titan, were not fully sterilized, as Titan's liquid oceans were discovered later. A Cassini mission scientist stated in 2017 that the probe "might be seeding life" on Titan.
The Stakes for Planetary Protection
Space agencies implement planetary protection protocols to avoid contaminating worlds that could harbor life, such as Enceladus, Europa, Mars, and Titan. The existence of resilient fungi may mean Earth microbes have already been introduced on Mars by previous rover missions.