21

The deciding factor is if the solar body has a chance of harboring life (or having done so in the past). Scientists don't want to run the risk of false positives: detecting life on another planet, only to find that we're the ones who brought it there. So probes sent to Mars are sterilized as best we can, while we don't sterilize probes to bodies that are ...


20

Quarantine was always a standard procedure for the astronauts which landed on the Moon. The Apollo astronauts were kept in quarantine just in case they contracted something on the Moon's surface. This turned out to be unnecessary, but better safe than sorry. But how likely is it that there are deadly pathogens on another planet? I would say it is pretty ...


12

It's one of several factors to prevent Earth microorganisms from contaminating the moon. The Apollo Program Summary Report states 8.5.2.1 Lunar-surface contamination.- Nations involved in the exploration of extraterrestrial bodies have agreed to take all steps that are technically feasible to prevent the contam- ination of these bodies during ...


11

Early Mars probes were heavily sterilized. Further studies have shown that Mars's surface isn't habitable, at least not in most areas, and thus a low risk approach has been developed, where certain sensitive parts are carefully controlled (Usually robotic arms), and missions to certain interesting places (Such as locations where liquid water is suspected) ...


11

Depending on exactly what temperature the water on Enceladus is, the answer is yes. Bacteria are an obvious choice. But there is a higher lifeform which can almost certainly survive: Tardigrades (Water bears) can survive for days at −200 °C - longer at higher temperatures, and can cope with extremely acid or alkaline environments. They can even survive in ...


10

Probably the closest thing to that environment on Earth would be Lake Vostok, which is 4 kilometers below the antarctic surface. Very little, if any, light gets down there, and it's really really cold, but still liquid. Scientists recently found bacteria living there, so it stands to reason that bacteria would survive on Enceladus, but the really amazing ...


10

One tool in the astrobiology toolbox is chirality, the property that many chemical compounds exist as "left-handed" and "right-handed" mirror images. These have the exact same properties of course, as they are the exact same compounds. But biochemical processes will typically only be able to produce one of them. Which means that if a ...


8

No. If there is a crash landing, then the Planetary Protection Officer (ESA's in the case of Schiaparelli) documents the crash location and the organic and biological material that was likely dispersed. This is available to all of the agency Planetary Protection Officers in order to provide information and advice for future missions to consider how that ...


6

There is an official Mars One FAQ page answering exactly this question: Mars One will take specific steps to ensure that the Mars environment (which we will study, and on which we will depend) will not be harmed. The Mars base will be forced to recycle just about everything, and pay close attention to its energy use and minimize the leakage of ...


6

There is actually a whole discipline, which deals with such issues (among others), in one way or another: Astrobiology. After reports of Streptococcus mitis on the Moon 1969/1970, the topic become more and more an issue of discussion. Today, there are sets of regulations on how a spacecraft, depending on its target, needs to be sterilized. This had led to ...


6

There's no need to worry about any viruses from Mars. If there are any, there would also have to be host organisms through which these viruses would multiply and survive (it's still debatable whether viruses even count as life). And host organisms are easier to detect through e.g. their metabolic process byproducts, and also more difficult to contaminate ...


5

You are correct that our current technology (e.g. polymerase chain reaction) allows us to easily distinguish and discriminate among life forms on Earth, and would allow us to readily identify Earth-derived life forms on Mars, should they survive. Even if Earth and Mars life ultimately have a common origin, we could still distinguish them from each other as ...


5

I can think of 3 reasons. The third is probably most important: 1. The point made by @Russell Borogove about common origin is one reason. We still don't know that much about the origin of life on Earth, so we certainly cannot rule out that possibility. 2. Another point is that we don't really know what alien life would look like. The only life we know of ...


5

If life on Earth and on Mars have a common origin (a microbial hitchhiker on impact debris, for example), contamination could obscure that fact.


5

Not completely, for a number of reasons, but in theory there should be less disease than on Earth. Some diseases last for a very long time, like AIDS. Things like the flu will have a really hard time making it to Mars. Some diseases have few symptoms, which makes them easier to hide. Lastly, things in space just tend to end up really germy. As a whole, ...


5

Nova Spivack explained in a tweet: We sent enough DNA to regenerate life on Earth, if necessary. Although it would require more advanced biotech than we have to do that. At least our DNA is offsite now. But note that cells & DNA cannot survive or reproduce on the Moon. Yet if retrieved they could be useful…


4

Article IX of the Outer Space Treaty requires parties to the Treaty to conduct their activities so as to avoid "harmful contamination" of celestial bodies, which would include Mars. This obligation also extends to the activities of commercial actors; Article VI of the Treaty requires States to ensure that their private actors' activities comply with Treaty ...


4

Once you open the hatch, Mars is contaminated. No matter how hard you try to sterilize everything before opening up, there will be microbes on the outside of suits, airlock surfaces, etc. Maybe you could flood the airlock with hot acid or some other biocide and then drain it, but that will be considered too much useless payload, and is not 100% guaranteed ...


4

While measures would be taken to limit the contamination for scientific investigation reasons, it is generally accepted that 100% containment would be impossible. In fact, when the planetary protection regulations were originally established in the mid 1960's, a time limit of 50 years was set as the time, for example, required that Mars orbiters remain in ...


4

It appears that most of the true sterilization actually takes place after launch. The harsh conditions of the trip there and the landing should be enough to kill off a majority of the microbes. The Mars rover projects all receive multiple sterilization treatments here on Earth before launch, typically UV treatment, but what really kills off the bacteria is ...


3

First, no that's not the reason it is one way, though it is something that is a matter of concern that has to be thought about. It's for reasons of cost and technology. Mars is a much harder place to land on and take off from than the Moon. That's because of the rocket equation The delta v to escape from Mars to orbit is 4.1 km / sec. To escape from the ...


3

The care which avoiding contamination space agencies take is generally proportional to the probability they assess of there being native life. Some of Saturn's moons are considered possible candidates for life, so Cassini was de-orbited. At this point, we are pretty sure that the Moon doesn't have life (no water, atmosphere, or significant magnetic field). ...


3

@Uwe answered my question The conditions on the Moon are the safeguard against anything biological from Earth reproducing itself outside a lander. Vacuum, temperature, lack of water, intensive UV radiation would kill any living unprotected cells. Moon is a perfect sterilization device. If a cell is not killed during hours there are a lot more days, weeks ...


2

One key aspect not mentioned so far is the possibility of contamination of Mars with Earth life that is not due to a failure of planetary protection. Carl Sagan was one of the first to suggest the possibility of cross contamination of life between Mars and Earth due to asteroid impacts as mentioned in his Cosmos series and as chronicled in "Carl Sagan'...


2

First of all, some effort is made to prevent contamination by earth organisms for precisely this reason, but it is not perfect. But, if scientists do detect life it will probably be possible to tell that it is not of earthly origin. Here are some possible lines of evidence: Biochemistry is complicated. We don't know that DNA is the only way genetic ...


2

The main concern is a lander (looking for life on Mars) bringing life to Mars and its instruments then detecting that life in a false positive. A crash landing makes that a non-issue: the instruments are no longer functional. Broadly, these are the goals of NASA's planetary protection rules: Preserving our ability to study other worlds as they exist in ...


2

After the fact, we now know that Curiosity is allowed to investigate the clay unit. The first clay sample was taken in April 2019 Later samples have verified findings about water in the Gale crater, and brought data about the clay's mineral contents. The same area has also been shown to contain salt deposits The rover has followed the possible trajectory ...


2

Vacuum is a harsh environment, so having the suit exposed to it should get rid of most bacteria. It is not a bulletproof method though, as confirmed by a famous case. Another good opportunity is to use UV sterilization, which offers to kill at least a good chunk of the bacteria. This can not possibly harm the suit, as they are designed to withstand sunlight,...


2

There actually just was a scishow video about this, where they said, that a specific kind of bacteria can survive in a simulated Enceladus ocean in the lab.


1

A recent and open access paper in Nature Biological methane production under putative Enceladus-like conditions describes an in-depth analysis of sources of energy in Enceladus' ocean and suggests that molecular hydrogen as H2 may be present and "eatable" by some organisms currently doing similar things here on Earth, e.g. Methanogenic forms of the Archaea ...


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