Forward ContaminationForward contamination is the transfer of life from Earth to another planet that can theoretically support life such as Mars. Life is extremely resilient. It is thought that certain types of microbes might potentially survive a space journey and the surface of Mars.If forward contamination were to occur, it could have a variety of impacts that might be impossible to reverse once they were set in motion. For example, if life exists on Mars it may be wiped out by a microbe from Earth. In theory, such contamination could evolve and eventually become an alien civilization. Scientists are also concerned that contamination from Earth could be mistaken for native alien life resulting in an erroneous scientific view of our solar system.Probes and unmanned spacecraft that visit a planet that could theoretically support life such as Mars can be sterilized to prevent forward contamination. Manned missions are more of a challenge because a typical human contains around 39 trillion microbes.
Back ContaminationBack contamination is the potential for alien life to contaminate Earth on its return. Missions may not want to sterilize returning samples if they have a goal of discovering alien life.Special quarantine facilities and procedures could be built to handle samples that may contain life such as soil samples from Mars. Back contamination is theoretically an existential risk as an alien microbe could cause environmental issues or a pandemic.
|Overview: Interplanetary Contamination|
The risk that life is transferred between Earth and an extraterrestrial body by a spacecraft or probe.