Back-contamination
Encyclopedia
Back-contamination is the informal but widely employed name for the hypothetical introduction of microbial extraterrestrial
organisms into Earth
's biosphere
. It is assumed that any such contact will be disruptive or at least have consequences over which human beings will have little control. The threat of back-contamination from the Moon
was the main reason for quarantine procedures adopted for the Apollo program, up until the completion of Apollo 14
. Astronauts and lunar samples were quarantined in the Lunar Receiving Laboratory
.
The likelihood that a human being or any other animal could literally acquire an alien virus
is effectively nil, as viruses are host specific. This does not mean that extraterrestrial microbes cannot act upon one pathogenically: spores might use an organism's body as hosts, while the ingestion of bacteria
in any form could produce toxic chemicals. When human beings ingest contaminated food, for example, they are not acquiring a virus in the manner of the flu but the experience may still be lethal because of toxic compounds.
Further, the possibility exists that a microbe might aggressively metabolize some Earth resource were it introduced here, altering atmospheric conditions
or the water cycle
.
Extraterrestrial life
Extraterrestrial life is defined as life that does not originate from Earth...
organisms into Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's biosphere
Biosphere
The biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system...
. It is assumed that any such contact will be disruptive or at least have consequences over which human beings will have little control. The threat of back-contamination from the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
was the main reason for quarantine procedures adopted for the Apollo program, up until the completion of Apollo 14
Apollo 14
Apollo 14 was the eighth manned mission in the American Apollo program, and the third to land on the Moon. It was the last of the "H missions", targeted landings with two-day stays on the Moon with two lunar EVAs, or moonwalks....
. Astronauts and lunar samples were quarantined in the Lunar Receiving Laboratory
Lunar Receiving Laboratory
The Lunar Receiving Laboratory was a facility at NASA's Lyndon B. Johnson Space Center that was constructed to quarantine astronauts and material brought back from the Moon during the Apollo program to mitigate the risk of back-contamination...
.
The likelihood that a human being or any other animal could literally acquire an alien virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
is effectively nil, as viruses are host specific. This does not mean that extraterrestrial microbes cannot act upon one pathogenically: spores might use an organism's body as hosts, while the ingestion of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
in any form could produce toxic chemicals. When human beings ingest contaminated food, for example, they are not acquiring a virus in the manner of the flu but the experience may still be lethal because of toxic compounds.
Further, the possibility exists that a microbe might aggressively metabolize some Earth resource were it introduced here, altering atmospheric conditions
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
or the water cycle
Water cycle
The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapor, and solid at various places in the water cycle...
.
See also
- AerobiologyAerobiologyAerobiology is a branch of biology that studies organic particles, such as bacteria, fungal spores, very small insects, pollen grains and viruses, which are passively transported by the air...
- AstrobiologyAstrobiologyAstrobiology is the study of the origin, evolution, distribution, and future of life in the universe. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry,...
- Extraterrestrial lifeExtraterrestrial lifeExtraterrestrial life is defined as life that does not originate from Earth...
- Forward-contaminationForward-contaminationForward-contamination is the contamination of other worlds with Terrestrial microbes. The risk of forward-contamination is twofold: that human beings may accidentally seed a previously sterile world, thus creating "extraterrestrials" that are really of terrestrial origin ; or that an...
- Living Interplanetary Flight ExperimentLiving Interplanetary Flight ExperimentThe Living Interplanetary Flight Experiment is an interplanetary mission developed by the Planetary Society. It consists of sending selected microorganisms on a three-year interplanetary round-trip in a small capsule aboard the Russian Fobos-Grunt spacecraft in 2011, which is a sample-return...
- Planetary protectionPlanetary protectionPlanetary protection is the term used to describe a guiding principle in design of an interplanetary mission that aims to prevent biological contamination of both the target celestial body and the Earth. This principle arises from the scientific need to preserve planetary conditions for future...
- Panspermia
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