Many thanks for your help (and patience) with my child-like query.

I proved my ignorance with the comments:

"One compromised bacterium?
One (or a dozen, or a few hundred) virus/viruses?"

It seems the standards (even for Mars) run into the 10s if not 100s of
thousands of micro-organisms as acceptable loads. But, to also answer
my own initial query, following the links provided I eventually found

http://www.astrobiology.com/protection.html

a site friendly (simple) enough to have probably precluded it in the
first place. Thanks.


I do find it curious though that the general response here seems that
as any earth organism would be unable to live/reproduce/thrive in such
an environment, consideration of their dispersal is rendered
uninteresting.


I suppose lurking in my uninformed thought was a notion of "earth
DNA" as potent information, even if not mechanically active. I
understand it is considered in the realm of possibility that bacterial
spores may possess integrity measured in "geologic" stretches...

"On the basis of such laboratory experiments, it has been proposed
that with proper shielding, bacterial spores might survive UV
irradiation for very long periods, perhaps millions of years."

from "Biological Contamination of Mars"
Space Studies Board / National Academy of Science
http://www7.nationalacademies.org/ssb/bcmarsch4.html



But I certainly don't mean to take up serious time here with what are
likely commonplace and perhaps adolescent wonderings. And I really
have no cranky axe to grind concerning this.

And if the last few decades might mark some potential exflorescence of
the terrestrial habit to the near and middle bodies of our solar
system, this hardly looms so very large in the wider view of things...
Thanks again.