Is this supposed to make the public feel relaxed that Martian soil samples are going to be brought back to Earth? And since as NASA claims, "no evidence for life on Mars has ever been found", the public should not worry.

Yet, terrestrial methane-making microbes have been shown to survive in Martian conditions

One of the most common misconceptions about bringing living microorganisms back from Mars is that because "Martian bugs" would have evolved independently of "Earth bugs", they will be harmless to life on Earth.

This theory assumes that Earth life has had millions of years of competitive struggle and that our ecosystem is so intertwined, that all forms of life on Earth bear similar hallmarks of their origins.

The theory continues that because of this similarity, and constant closeness is what makes microbes effective enough to cause to cause harm and that a "Martian microbe" would not "know where to begin" and that any feeble attempts at "learning" how life on Earth "operates" to take advantage of, would be "fended off" by immune systems with millions of years worth of head start. I hear this argument coming out of NASA and the science community.

However, the alarming truth is that Martian microbial life would not have to "learn" how Earth life "operates" at all. All that is required is that Martian microbes find Earth-life to be a good source of food, and then has the capacity to harvest it.

In fact, even Earth microbes do not know how life on our planet "operates". Terrestrial microbes merely use humans, animals and plants as food.

All higher life on this planet has evolved to the context of the microbial life that exists here. That is, it evolved to cope with the latter's constant incursions.

There is NO guarantee no matter what the Space Studies Board or NASA suggest. In fact, it is unlikely that terrestrial animals and plants could withstand attacks of alien microbial life which it has not evolved to cope with.

All any Martian microbe has to do is perceive Earth life as a source of food and then have the capacity to "harvest" it. For example, if Martian microbes had amino acids similar to terrestrial life and liked some of the same small carbon compounds -- that would be enough to make us attractive to them.

Earth microbes might in turn, find the Martian microbes a good food source, but by no means does that imply they would wipe it out. When the entire biosphere hangs in the balance, it is adventuristic to the extreme, to bring Martian microbes directly to the surface of the Earth as is now planned.

Sure, there is a chance it would do no harm; but that is not the point. Unless you can rule out the chance that it might do harm, you should not embark on such a course.

As co-founder of the International Committee Against Mars Sample Return (ICAMSR), I along with hundreds of other members, feel that more in-situ life sciences experiments are needed to look for additional evidence for life on Mars.

Dr. Gilbert V. Levin, former Viking biology team experimenter, says his biology instrument flown to the surface of Mars in 1976 (which tested the soil of Mars nine times) detected living microorganisms.

Yet Levin is ignored by the policy makers behind the Mars Sample Return mission. Why? The MSR capsule will enter Earth's atmosphere directly in the year 2008. It will not have a parachute. What's more is that the seal on the Mars Sample Return capsule is going to be welded shut in Martian orbit.

How will we know for certain the capsule will be properly sealed without a human inspection crew in Earth orbit? Perhaps the Russian Space Station MIR could be modified and kept running for this future task.

This would prevent possible contamination by martian microbes of the multi-billion dollar International Space Station, if it was used for such a purpose. The whole point is, there are other alternatives than returning Martian soil samples directly to the surface of the Earth.

Every possible contingency must be considered, because all it would take is for one replicating martian organism to take hold and harvest our ecosystems.

Editor's Note: This opinion piece is published in the interests of fair and open debate and does not reflect the opinions of SpaceDaily one way of the other.

Barry E. DiGregorio is the founder of the International Committee Against Mars Sample Return