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ChromeStar
2005-Jan-03, 06:09 PM
Hi guys :D

there have been many probes sent to other worlds in our solar system to look for things like life, but how can they be sure that we have'nt sent our own life there by mistake.

As of now no other extraterrestrial life has been discovered in our solar sytem but what if it's one day discovered, how will we know it's not our own?

How will they prevent our microbes from getting a ride to the next planet?

antoniseb
2005-Jan-03, 07:04 PM
Originally posted by ChromeStar@Jan 3 2005, 06:09 PM
How will they prevent our microbes from getting a ride to the next planet?
That is a good question, that does get some consideration. Organisms inadvertantly sent to the moon on a Surveyor lander were brough back alive by the Apollo twelve crew. Several years of exposure to radiation, extremes of temperature, and hard vacuum did not change live spores into dead spores.

Some forms of life are simply not very fragile, and are perhaps the sort of life that would "thrive" in alien environments like Mars or Io.

John L
2005-Jan-03, 08:06 PM
Why would you want to stop it? If we are going to learn to explore the solar system, and then eventually the galaxy, we'll have to learn to live off the land where ever we go. The first step is to find out what life on Earth can survive out there and what life we need out there to make life livable. If that starts out with a few mistakes that send Earthly life to the worlds of the solar system, then we'll have learned the first thing needed to know how to get off of this little ball of rock for good.

Nyrath
2005-Jan-03, 08:43 PM
Well, one reason to try and stop it was illustrated many decades ago, when rabbits were introduced into Australia.

It is real hard to live off the land when the ecosystem gets wreaked.

John L
2005-Jan-03, 10:50 PM
There are no Human supporting ecosystems in the solar system to wreck, beyond the Earth that is... If we found that Ganymede was covered in verdent grasslands, then I'd agree with you. When its ice and rock on an airless moon, though, we need to actually start an ecosystem first. Then we send in the rabbits! ;)

Bobunf
2005-Jan-04, 06:48 AM
It’s seems to be that the reason to avoid contamination of potential habitats for life in the solar system is to preserve the possibility of the study of comparative biology. If we were to find life on Mars, or anywhere else, there wold be great value to learning everything possible from it. We would have much enhanced insight into all kinds of issues:

Is there another chemistry for life than the biochemistry on Earth? What’s necessary for life? How do the adaptations to the new environment work? What’s genetically new, and unique, on Mars?

Even if life on Mars had a common origin with life on Earth, the divergent, isolated, evolution for four billion years, or even a few million years, in a completely different environment would greatly enhance our understanding of how life works.

The enhanced understanding of biochemistry, the architecture of life, evolution, and dozens of other subjects could lead to biological breakthroughs we can’t currently imagine. The consequences for medicine could be enormous. We would have a much enhanced understanding of the origin of life, of its paths of progression, and its probable incidence in the rest of the universe.

I don’t think we’re likely to derive any benefit from a native ecosystem on Mars or anywhere else in the solar system, except that which it bestows on scientific research. But that could be very substantial indeed.

Bob

GOURDHEAD
2005-Jan-04, 01:22 PM
The enhanced understanding of biochemistry, the architecture of life, evolution, and dozens of other subjects could lead to biological breakthroughs we can’t currently imagine. The consequences for medicine could be enormous. We would have a much enhanced understanding of the origin of life, of its paths of progression, and its probable incidence in the rest of the universe. I agree. We will be forced to study and understand any non-Earth native life found wherever we go. The microbes of such a system will include pathogens that we must learn to cope with.

Bobunf
2005-Jan-04, 02:44 PM
"The microbes of such a system will include pathogens that we must learn to cope with."

I think I'd change the wording to something a little less definite:

"The microbes of such a system may include pathogens that we might have to learn to cope with."

ChromeStar
2005-Jan-04, 08:10 PM
The enhanced understanding of biochemistry, the architecture of life, evolution, and dozens of other subjects could lead to biological breakthroughs we can’t currently imagine. The consequences for medicine could be enormous. We would have a much enhanced understanding of the origin of life, of its paths of progression, and its probable incidence in the rest of the universe.
I agree. We will be forced to study and understand any non-Earth native life found wherever we go. The microbes of such a system will include pathogens that we must learn to cope with.


I agree with both Bob, GROUNDHEAD and Nyrath

ChromeStar
2005-Jan-05, 07:26 PM
What do you think of this?

if a space craft flew close past the sun would that kill of any microbes?

John L
2005-Jan-06, 10:13 PM
From the Surveyor example on the Moon we already have contaminated Venus, the Moon, and Mars with Earth microbes, and will contaminate Titan on January 14, 2005 with the Huygens probe. Europa is still clean, and we can keep it that way. The point of this thread is preventing Earth life from piggy backing with a probe sent to study life. Is there anything that can kill off Earth microbes, though? Surveyor showed us that radiation and a hard vacuum for years isn't enough. Deep sea vents, geysers, and Antactica show us that hot and cold don't work. There is life in high saline, high acid content water as well, and even bacterial that can live off of toxic waste and petroleum. So what can be done to ensure a totally sterile craft being sent to even look for life, let alone protect it from contamination? We lack the technology right now to do it and not destroy the probe in the process.

Ola D.
2005-Jan-08, 09:38 AM
Bacteria is flexible in living.
I don't see any harm if by coincidence a certain type of Earth bacteria survived living on Mars or Titan. So, it's not always a disadvantage.

ChromeStar
2005-Jan-08, 11:06 AM
yes that is true, but even microbes that live in extreme heat can't handle thousands of degrees - Or can they? :huh:

antoniseb
2005-Jan-10, 02:20 AM
Originally posted by ChromeStar@Jan 8 2005, 11:06 AM
yes that is true, but even microbes that live in extreme heat can't handle thousands of degrees - Or can they? :huh:
No they can't, and neither can electronic instruments.

ChromeStar
2005-Jan-10, 07:40 PM
Perhaps when Newer more advanced Materials are developed this may be a means.

What do you think?

spacepunk
2005-Jan-18, 06:54 PM
Bacteria is flexible in living.
I don't see any harm if by coincidence a certain type of Earth bacteria survived living on Mars or Titan

I've read somewhere how the corallory is hypothesized to be true. That is, some comets or meteorites could introduce a flu bug into Earth that originates from elsewhere in the solar system. Might be a red herring though, because this sounds like the claims of possible disease spreading in 1910 when Earth passed through the tail of Hailey's Comet. At that time all sorts of elixors and alchemist medicines were available from travelling salesmen to treat for a supposed affliction! Might be some substance to the concept though

GOURDHEAD
2005-Jan-19, 03:13 AM
Bacteria is flexible in living. I don't see any harm if by coincidence a certain type of Earth bacteria survived living on Mars or Titan. The harm could arise by the effects of Earth bacteria on Titan's indigenous life forms. Also, afterwards it'll be difficult to know for sure whether the bacteria were native to Titan or not.

spacepunk
2005-Jan-19, 10:42 PM
Bacteria is flexible in living

There will always be the academic questions of possible natural interstellar contamination from other solar systems, or from other planets/moons/comets in our own solar system by means of meteors and comets.

The whole idea of not wanting to introduce Earth organisms into another biozone in our solar system may be unworkable anyway. Fungal (mould) spores, but also algeal sporesl float unimpeded high up in the atmosphere and could re-contaminate a so-called clean space ship.

Bobunf
2005-Jan-20, 12:30 AM
"The whole idea of not wanting to introduce Earth organisms into another biozone in our solar system may be unworkable anyway. Fungal (mould) spores, but also algeal spores float unim-peded high up in the atmosphere and could re-contaminate a so-called clean space ship."

This is certainly true. But contamination could also occur because it is nearly impossible to 100% sterilize anything that you want to use for something later. There have also been an awful lot of spores, bacteria and other living things introduced into geo-synchronous orbit from which long term travel to the Moon or other celestial bodies is quite possible. Spacecraft have also been sent to the Earth-Sun LaGrange 2 point, and many other places, which might bear the risk of long term contamination of other bodies.

It’s also possible that Earth life has traveled on numerous occasions from ejections produced by impacts on Earth.

I certainly think it’s worthwhile to try to prevent contamination to the extent feasible for as long as possible. The problem with such a statement is that can be enlarged beyond reason.

For instance, no manned exploration of Mars, or anywhere else, is possible if it is insisted that contamination be indefinitely avoided. It's also true that we will never know with confidence that there is no life on Mars, or any other possible habitat, without direct human involvement.

And that leads to the circular, “No manned exploration until lack of life is certain. Lack of life can’t be determined without manned exploration.”

One is tempted to say, “Be reasonable.” But many people aren’t.

Bob

ChromeStar
2005-Jan-20, 08:27 PM
You make a good point. There are microbes and even small spiders that are lifted to the edge of the atmosphere because they are so light.

For all we know they have already been transported by solar winds etc... to planets in our system and beyond - if i'm not mistaken this is a theory that predicts life spreads like this, it's similar to the comet idea.


One is tempted to say, “Be reasonable.” But many people aren’t.

You're good at that, i need a good dose of cold water now and then ;)

Spacemad
2005-Jan-20, 09:57 PM
Originally posted by spacepunk@Jan 19 2005, 10:42 PM

The whole idea of not wanting to introduce Earth organisms into another biozone in our solar system may be unworkable anyway. Fungal (mould) spores, but also algeal sporesl float unimpeded high up in the atmosphere and could re-contaminate a so-called clean space ship.

Spacepunk, The extract I've quoted from your post reminded me strongly of a chapter in Issac Asimov's novel "Foundation & Earth" published in 1986, in chapter XV titled: "Moss" . There the protagonists of the story land on a world once inhabited by humans but now abandoned with a very, very tenuous atmosphere, incapable of sustaining life. They explore a city on this world & after a few hours one of them notices that around the seals of the other´s helmet something green has appeared. On closer examination they conclude that some kind of moss has germinated & is growing around the seals. As they find the same kind of moss growing in cracks out of the sunlight they deduce it must feed on the Carbon Dioxide from the disintegration of the stone. They then decide that the filtrations of air from their spacesuits must be very much richer in CO2. They discover it dries up & dies in the direct sunlight. They return to their ship but before getting onboard the captain , using his "blaster" in the minimum setting(which only produces heat) gives the ships seals a good going over. They then board the ship where the two men using the blaster set to min. clean their suits & the interior of the airlock with the heat to destroy any spores that might have entered with them. On entering the ship they order the ultraviolet light to be turned on & take of their inner clothes & expose them, inside & out, to the UV light.

Once they abandon the planet the captain orders that the ship be taken as close as possible to the planet´s star, to expose as much as possible of the ship to the sterilising functions of heat & UV light

He argues to his crew that the merest amount of spores that should survive could germinate on another world & infect everything & perhaps cause the death of every living thing that breathed out CO2 as it would grow so incredibly fast & multiply so fast that all living organisms would be suffocated in a very short time.

:( Sorry if this has gone on so far but I wanted to illustrate a point, if a strange form of life should infect another world different to where it originated the effects could be disastrous!!! (as the captain in the story realised!).

But we needn´t go as far as that for another example, much closer to home: that of the rabbits introduced into Australia! Everyone knows (the Aussies especially!!!) what a plague they have become as they had no natural enemies to keep their numbers down! There are now countless millions of rabbits in Australia!!!

So those who don´t give much importance to other worlds being infected by Earth organisms - take warning!!! :rolleyes:

Ola D.
2005-Jan-21, 01:50 AM
Originally posted by GOURDHEAD@Jan 19 2005, 03:13 AM

Bacteria is flexible in living.* I don't see any harm if by coincidence a certain type of Earth bacteria survived living on Mars or Titan. The harm could arise by the effects of Earth bacteria on Titan's indigenous life forms. Also, afterwards it'll be difficult to know for sure whether the bacteria were native to Titan or not.
Yes, but my point is that it'll be also a good achievment if Earth bacteria accomodates Titan's conditions for instance. Probably we'll miss the chance of being introduced to the native life of Titan; on the other hand, another result was concluded and a whole new discovery was found.

After all, many discoveries in science were found by coincidence. For example, Penicillin would've not been discovered to act like an antibiotic against bacteria if the fungus Penicillium didn't accidently enter the petri dish of Alexander Fleming, even though he carefully maintained a sterile condition.

Coincidence can be productive sometimes.

spacepunk
2005-Jan-21, 02:12 AM
Sorry if this has gone on so far but I wanted to illustrate a point, if a strange form of life should infect another world different to where it originated the effects could be disastrous!!! (as the captain in the story realised!).

But we needn´t go as far as that for another example, much closer to home: that of the rabbits introduced into Australia! Everyone knows (the Aussies especially!!!) what a plague they have become as they had no natural enemies to keep their numbers down! There are now countless millions of rabbits in Australia!!!


I think you've addressed the risks associated with transferring life from one biozone to another quite well. During the time of the Apollo missions a movie was made called the "Andromeda Strain".

Examples other than rabbits in Aussie country exist in North America: the dandelion (aka Scourge-of-the-Golf Course) which were knowingly transplanted, and most recently Asian ladybugs that flew/floated from Asia to north America in the same manner that ChromeStar indicated with small spiders. Normally they feed on aphids, but with temporary overpopulation for a couple of years they resorted in some cases to developing a sweet tooth for eating fruit!!!!

The best answer to all this is to develop some solid safety protocols, as was adopted by the characters in the Asimov novel. Hopefully it will be enough!! :)

Bobunf
2005-Jan-21, 03:31 AM
Has anyone noticed that the examples of dangerous biological infestations seem kind of funny?

There’s one thing in common with all of the examples: rabbits, dandelions, spiders, ladybugs. The damage is as nothing compared to that wrought by fellow occupants of our space: plague, yellow fever, smallpox, cholera, malaria, and closest of all, cancer.

I’m pretty sure that rabbits, dandelions, spiders and ladybugs combined, whether native or not, cause far fewer human deaths than homicide by close friends and relatives or suicide caused by the selfsame individual.

Maybe the danger of biological contamination is a bit over blown?

Bob

spacepunk
2005-Jan-21, 02:44 PM
Maybe the danger of biological contamination is a bit over blown
I agree Bob, as probably do most of the respondents here.

But to keep from being reckless one has to present a forum for valid scientific disention from scientifically or politically accepted theories. Eventually a theory in science becomes a "Law". That is, regardles of standard (scientific) acceptance of the "theory of evolution" it is not (politically) accepted in some societies nor in most(yes I said "most", not "all") religious circles. I haven't heard say, National Geographic, declare it the "Law of Evolution". Quite a departure from the "Law of Gravity" whereby its not just a theory anymore. Of course some people still believe in a flat earth and other Bad Astronomy website material.

You yourself said "One is tempted to say, “Be reasonable.” But many people aren’t." Everyone has their own opinions but the facts will eventually determine a proper risk assessment.


The damage is as nothing compared to that wrought by fellow occupants of our space: plague, yellow fever, smallpox, cholera, malaria, and closest of all, cancer
That Hailey's Comet theory actually gained some momentum in about 1918 with the outbreak of the spanish flu. Some claimed it was an invasion of a germ from space ... I'm not qualified to comment on that, but it could, by some people, be compared with the origin of other afflictions as per this other quote from you.

Ladybugs are intrinsically harmless, you're right. That's what the risk probably boils down to from space microbes but someone else may strongly disagree with that statement! Better to develop some safety protocols to rule out recklessness on our part.

Bobunf
2005-Jan-22, 11:30 PM
"theory in science becomes a 'Law'"

Theory and law have precise scientific meanings. Theories never, ever become laws. A theory is an explanation, the highest possible culmination of scientific endeavor. “A theory is an established paradigm that explains all or many of the data we have and offers valid predictions that can be tested. In science, a theory can never be proven true, because we can never assume we know all there is to know.”

A law is an observation, a lowly thing, hardly to be regarded, ready to be overthrown with no pomp whatever.

Thus we have Bode's Law, little more than poetry. Or Kepler’s laws, observations of planetary motion only explained, and more accurately determined, by Newton and later by Einstein’s General Theory of Relativity.

F = G*(m1*m2/r^2) doesn’t explain anything. That’s just how we’ve seen things work. Why the relation between m1 and m2? Why is r squared? Why not cubed; after all the volume is cubed? For answers, look to theory.

Remember: Laws never become Theory. Laws have no place to go, but down. But, even then they’ll be fondly remembered; they are so simple.

Bob

jamerz3294
2005-Jan-23, 07:45 AM
Not contaminating other panets is a major concern of scientists, and also NASA. It would be very embarasing o annouce that life has been found onanother planet, only to discover later that we brought it there!
But, realistically, we humans will pollute each and every place we venture to. So just how much flora and fauna on any new palnetwill be untainted? And how much wil the various strain of microbial life mutate, and then become malignant when we bring them back to earth?

spacepunk
2005-Jan-23, 07:53 PM
One is tempted to say, “Be reasonable.” But many people aren’t.
What's great about having a forum at all on any subject is that in the end the facts should speak for themselves. However not everyone will draw the same conclusion.


Laws never become Theory. Laws have no place to go, but down. But, even then they’ll be fondly remembered; they are so simple
Many lawyers would agree with your analysis. But more than a few people including lawyers would strongly disagree with that statement. They'll insist no law is simple and you should retain legal consul to interpret any law. Lawyers chuckle at the concept that someone going into a courtroom acting as their own lawyer has a fool for a client. Perhaps you could refer to some simple laws out there adherred to in the courts of scientific inspection? Even Murphy's law can go wrong sometimes so it must be just a Theory.


Not contaminating other panets is a major concern of scientists, and also NASA
Talk about environmental stewards. I'm sure that these people wouldn't want to be the subject of possible litigation if in effect they were negligent to the extent of the following preventablecompromised biosecurity situations:

zebra zussels (http://www.great-lakes.net/envt/flora-fauna/invasive/zebra.html)
emerald ash borer (http://www.na.fs.fed.us/spfo/eab/)
weed (http://tncweeds.ucdavis.edu/esadocs/documnts/holclan.html)
weed (http://www.npwrc.usgs.gov/resource/1999/loosstrf/loosstrf.htm)
more weeds (http://invader.dbs.umt.edu/blackfoot/spp_summ.htm)


and of course the transplanting around the world of

plague, yellow fever, smallpox, cholera, malaria,

Bobunf
2005-Jan-29, 08:36 PM
The meaning of “law” in science has no relation at all to the meaning of “law” in jurisprudence. “Dig” doesn’t mean the same thing in archeology as it does in music. “There” doesn’t mean the same as “their.” “Dog” doesn’t mean the same thing as “dram.” Etc.

Here is an example of a simple scientific law, Kepler’s First Law of Planetary Motion: All planets move about the sun in an elliptical orbit with the sun at one foci.

This law may or may not always be true; but even if it were always true 100% of the time no matter what the circumstances, it still wouldn’t ever be a theory; only a law. It doesn’t explain anything. It doesn’t tell why, or how it comes about, or what are the underlying mechanisms, or how the result can be modified?

Laws that are wrong, stay laws; they certainly don’t turn into theory; Bode’s Law is an example; nobody would think of calling it Bode’s Theory.

Murphy’s law doesn’t exist in either science or jurisprudence, but it is only an observation, not a theory in a scientific sense. It can never rise to the level of theory; that would require an explanation as to why the observations occur; an understanding of the processes that produce the ob-served (and unobserved) effects.

Then it would be something different, Murphy’s Theory as to why and how if anything can go wrong, it will. The Law would still be there; unattached to, hardly relevant to, the theory.

“All planets move about the sun in an elliptical orbit with the sun at one foci” doesn’t explain anything. It just says what happens; it’s just a law.

Bob

trevorsproston
2005-Jan-29, 10:48 PM
Hello.

I know this isn't strictly relevant, but I'm involved in Space Education in the UK, and I'm putting together a simulated Martian sampling scenario for publication.

It involves the collecting and growing of samples of living things [plants, moulds, microbes etc], which can be obtained via the simple method of using sticky tape on various outdoor surfaces.

I can easily buy ready-made growth medium, but as this is intended for home experimentation [with obvious caveats], I'd like to know if there is a simple growth medium which can be made with domestic ingredients. I'm currently trying out a plain gelatine/sugar mix.

Does anyone have any ideas?