Terrestrial sanitation.....

[Belacqua]

UGGGGGG!

Way to miss the point.

I understand your point. You are interested in discovering whether life can exist on other planets. You think that if we take some there, it would prove the point.

I agree that if we take life to another planet and it survives, then we have proved that point. 

I'm making a different point. 

If we want to know whether there is already life indigenous to another planet, we shouldn't take our own. It would be likely to interfere with the research.

[BrianSoddingBoru4]

There is a longstanding thought in space exploration that you sanitize all equipment when sending it to other celestial bodies to insure that your findings won't give you a false positive that what you find might give you the false impression that the life you think you have discovered originated from another body.

Here is my question, WHY is this important? I would think that if would be more important to prove our life can exist on other bodies. That would prove life is possible elsewhere.

For example, it would NOT surprise me if we sent tardigrades to the poles of Mars or Pluto and could prove our life could survive on other bodies.

What Bel said.  You're confusing two different lines of research.  If we want to determine whether or not life had evolved on Mars, we'd want to take precautions that we don't contaminate the field with terrestrial life.  If, on the other hand, we want to determine whether or not terrestrial organisms can survive on Mars, then we'd bring some along.

You design your experiments based on what you're trying to find out.

Boru

[Paleophyte]

There is a longstanding thought in space exploration that you sanitize all equipment when sending it to other celestial bodies to insure that your findings won't give you a false positive that what you find might give you the false impression that the life you think you have discovered originated from another body.

Here is my question, WHY is this important? I would think that if would be more important to prove our life can exist on other bodies. That would prove life is possible elsewhere.

For example, it would NOT surprise me if we sent tardigrades to the poles of Mars or Pluto and could prove our life could survive on other bodies.

Several problems with this:

 - While it might demonstrate that life that evolved on Earth could adapt to a few extraterrestrial environments it would not demonstrate that life had arisen there. This is of limited value, especially since we can reproduce many of those environmental variables right here on Earth.

 - The discovery of extraterrestrial life that had arisen and evolved entirely separately from our terrestrial lineage would be of incalculable scientific value. What you're suggesting would make burning the Amazon look like an act of charity.

 - Populating extraterrestrial bodies with terrestrial species and letting them evolve in a hostile environment with few constraints is an excellent way to ensure that sooner or later we bring back something that's very good at chewing on us or some vital part of our ecosystem. Exotic species are not your friend as any Australian can tell you.

[ignoramus]

maybe Brian just wants to "make" new friends

[AFTT47]

There is a longstanding thought in space exploration that you sanitize all equipment when sending it to other celestial bodies to insure that your findings won't give you a false positive that what you find might give you the false impression that the life you think you have discovered originated from another body.

Here is my question, WHY is this important? I would think that if would be more important to prove our life can exist on other bodies. That would prove life is possible elsewhere.

For example, it would NOT surprise me if we sent tardigrades to the poles of Mars or Pluto and could prove our life could survive on other bodies.

Several problems with this:

 - While it might demonstrate that life that evolved on Earth could adapt to a few extraterrestrial environments it would not demonstrate that life had arisen there. This is of limited value, especially since we can reproduce many of those environmental variables right here on Earth.

 - The discovery of extraterrestrial life that had arisen and evolved entirely separately from our terrestrial lineage would be of incalculable scientific value. What you're suggesting would make burning the Amazon look like an act of charity.

 - Populating extraterrestrial bodies with terrestrial species and letting them evolve in a hostile environment with few constraints is an excellent way to ensure that sooner or later we bring back something that's very good at chewing on us or some vital part of our ecosystem. Exotic species are not your friend as any Australian can tell you.

Beat me to it but I will add my voice for emphasis:

The whole point of avoiding contamination is to help establish that life came about twice in our own solar system independently. This is very important because we currently have a sample size of one. That is statistically useless. We can say intuitively that surely, life must have come about elsewhere in this vast universe but that is not scientific. But if we could point to TWO verifiable independent examples of life arising in our own solar system, we could scientifically make the claim that life (at least simple life) must be everywhere. We cannot do that with a sample size of one (Earth).