When the Europeans conquered a "new world" they brought all their knowledge and technology together with their diseases.
These diseases killed many people. Now that humans are ready to travel to other planets in search of life,
we must ask, "have we learned our lesson?"
Planetary protection is a new field that is trying to answer this question and others, such as:
- How can we protect other worlds from microorganisms found on Earth?
- How can we protect other bodies from forward contamination?
- How can we protect Earth from backward contamination?
First of all, when we are searching for extraterrestrial life we don't want to falsely register some Earth microbe
incidentally left on the spacecraft as an "extraterrestrial microorganism".
Second and most important, we have to be aware of the deadly consequences that contamination may have.
Microorganisms from Earth could colonize the planets we visit.
These foreign microorganisms could harm, change or even kill the indigenous planetary life.
Forward contamination is a term used to describe the transmission of microorganisms from Earth to other planets.
Microorganisms from Earth could infect another planet, harming existing life on that planet or "seeding" a lifeless
planet with microorganisms from Earth. If the life on the other planets is completely different from what we know on here on Earth,
protection from possible contamination will be challenging because we won't immediately know how the extraterrestrial life is harmed.
NASA scientists are aware of the possibility of contamination and do their best to prevent contamination.
All spacecraft are built in clean rooms in which workers wear gloves and booties, and where air vents suck up airborne microorganisms.
Everything is sterilized with an alcohol solution and the room is sealed from outside air.
Backwards contamination is the introduction of extraterrestrial microorganisms to Earth.
Bringing back to Earth samples from planets, moons and other bodies is very exciting but should be
treated with caution.
Samples should be sealed and carried in special containers.
They must be under quarantine and carefully examined in specially sealed facilities before they can be
released for further scientific analysis.
The need for backward planetary protection first arose after the lunar landings.
Astronauts were dressed with biological isolation garments and were quarantined in a special
sealed facility after their flight to the Moon.