Question: why Perseverance has been sent where water was instead of where water (likely) is? : PerseveranceRover
https://www.reddit.com/...eranceRover/comments/lsahwq/question_why_perseverance_has_been_sent_where/
smithery1
3 hours ago · edited 3 hours ago
The Perseverance mission is to study ancient life, not current life. This distinction is intentional and meaningful. There are many areas on Mars "likely" to contain life, and Jezero isn't one of them. These areas with potential life (meaning basically water nearby) are termed "special regions", and missions avoid them to prevent "forward contamination" - the introduction of foreign organisms from Earth to the other body.
An international committee named COSPAR produces recommendations on how to avoid forward contamination in all sorts of scenarios. As the likelihood of encountering foreign life increases for a mission, the strictness of the requirements goes up as well. These include trajectory biasing so a flight failure at any point in the mission does not crash in a special region, clean room and decontamination on Earth, etc. etc.
Spacecraft in special regions must have no more than *30* total spores. Perseverance went through an incredible cleaning produce during assembly, with clean rooms inside other clean rooms, heated parts, special solvents, etc. All that effort has a target of *300,000* total spores on the spacecraft, with *41,000* spores on the rover alone.
So meeting the forward contamination requirements is a very high burden. To ensure Perseverance doesn't destroy any life that may currently exist, it instead searches for life that may once have existed. If there *is* life on Mars, there *was* life on Mars, and we can safely search for evidence of that.
References:
Perseverance Biological Cleanliness,
Planetary Protection,
Mars Special Regions