First Contact – The
Germ Scenario
By James and John
Gaines
The
February, 2015 issue of Popular Science
has a thought-provoking article by Corey S. Powell entitled “Have We Found
Alien Life?” (pp. 34-39 and 70). It
reports on the research by USC scientist Kenneth Nealson into a one-celled
organism called Shewanella oneidensis that appears to be able to grow uniquely
on the charges from an electrode. This
allows the bacterium to “breathe rocks” in a way unlike other earthly
creatures, but perhaps like others that may be discovered eventually in outer
space. The article goes on to examine,
in parallel, possibilities of microbial life on other planets of the solar
system and ways to go about detecting it.
Nealson’s
discoveries, while not oriented specifically towards alien biology, bring up
the sensible scenario that when we make contact with other-worldly life, it may
be us doing the contacting, and the life may not be intelligent by any existing
standards. Of course, this type of first
contact scenario poses a number of significant risks that have been imagined in
part by science fiction in the past. H.
G. Wells’s War of the Worlds treats
the matter in reverse, since technologically superior and malevolent Martian
invaders are eventually laid low by germs from earth. B-movies of the 1950’s were concerned, in
contrast, with the dangers to Earthlings from germs that would come to earth
accidentally. In the case of The Blob, an amoeba-like organism
survives inside a meteor and winds up absorbing the tissues first of an
imprudent hermit and then of much of the population of an isolated town. Invasion
of the Body Snatchers imagines a
different sort of cosmic fallout in the form of spores that grow first into
exaggerated peapods and then morph into humanoid form, taking over the psyche,
as well as the body, of the nearest human.
These pod creatures are not strictly speaking microbial or one-celled,
but the idea is similar. Other films,
such as The Crawling Hand, feature
some kind of contagion that comes back to Earth with a space explorer and
spreads (in this instance with merciful slowness) into the human race before it
is stopped. It is not quite clear in The Crawling Hand that the organic
processes are due to a new species or simply to radiation-induced mutations of
human cells, but as one can deduce from the title, this drive-in fare is more
concerned with the sexual attributes of its “Swedish” female lead than with
hard sci fi.
In more
recent times, the discovery of quasi-microbial remnants in meteorites and the
apparent evidence of water on Mars have revived speculation about microbial
life that could be soon proven on one of the near worlds. Some anxieties have arisen over the possible
contamination of our own ecosystems by these strangers. During the exploration of the Moon by Apollo
astronauts, there had been relatively little concern that moon rock samples
might pose any dangers. For one thing,
there was ample evidence that the Moon would be sterile, given the fact that
water was not positively identified there until after the missions were
finished. Secondly, the samples were
quite limited and were subject to careful scrutiny. Thirdly, the astronauts themselves functioned
to some degree as canaries in the coal mine, since the return to Earth was not
instantaneous and any glaring peril might presumably unveil itself during the flight
back. After extended examination, moon
rock samples were eventually distributed far and wide, so the fact that they have
produced no discernible damage proves retrospectively that any anxieties were
unnecessary.
However,
this comforting lack of extraterrestrial life so far may not hold true for
future expeditions. Asteroids, the
immediate target for NASA missions, might seem to pose no greater danger than
the moon rocks. We must keep in mind,
though, that one important goal of asteroid encounters is potential
mining. One wonders if importation of
tons of material would be treated with the same scrupulous care as NASA’s tiny samples,
especially if the goal were not pure science, but commercial
capitalization. This still limited risk
is multiplied many times when it comes to samples from some of the other
interesting bodies in our solar system, such as the moons of Jupiter, Saturn,
and Neptune. Besides satellites like
Triton and Europa, which might have submerged liquid seas, other worlds may
sustain underground microbial life.
Powell’s article specifically mentions Mars, Titan, and Ganymede as
places that might sustain rock-consuming microbes not dissimilar to the ones
discovered by Nealson and his team. In
regards to the Saturnian moon of Enceladus, Powell says, “hydrothermal vents
below its South Pole… would be natural homes to rock-breathing microbes”
(35). NASA certainly embodies much of
mankind’s present knowledge about biochemical contamination and could be
counted on to apply what it knows, but in view of severe budget restrictions
and the general neglect of much hard scientific R & D on a worldwide scale,
we wonder if what we know now might really be enough to protect our planet
against possible contamination.
In this
regard, two additional B-movies deserve consideration. It! The
Terror from Beyond Space and 20
Million Miles to Earth postulate more substantive imports in the form of
vaguely reptilian and bipedal creatures that are brought back on
spacecraft. In It!, the importation is strictly involuntary and unknown until
after the return trip is initiated. The
ET kills several of the crew and menaces others before a drastic solution is
found in the form of depressurization of the ship. This was a good enough idea that it was
duplicated years later in the film Alien, where the danger of exposing Earth to
its dragon-like creature was far more explicit.
In 20 Million Miles, on the
other hand, the importation is deliberate and the Venusian is thought to be
utterly harmless until it is exposed to the air and rocks of Earth, which make
it grow into a giant that terrorizes Rome before succumbing to a mere bazooka. Leaving behind the sensational appearance of
both monsters, let us ponder the means of transmission rather than the
exterior, since a real danger may not come from something that roars or looks
like a dinosaur. The It! scenario, where a stowaway bacterium
would not be discovered until it is already on the way to Earth and holds, so
to speak, a human crew as hostages, is a frightening possibility. In a worst case, it might lead to the
termination of the mission and its human component. A 20
Million Miles eventuality might be all the more ghastly, since control on
our own planet could not be preserved simply with nets or bazookas.
Returning
to the Nealson characterization of his organism as “rock breathing,” it may be
worthwhile to examine a particular risk of an organism “hiding” itself inside
the Earth. Humans generally tend to
think of the Earth as a vast machine for decontamination, rendering harmless
everything from nuclear waste to plague remains. However, what if a rock breathing
microorganism got under the surface of our most important rock – this
planet? We who are mainly limited to
controlling the surface of the planet do not currently possess the means to
reasonably decontaminate the Earth itself I an alien microorganism managed to
establish itself below us. What could be
the potential effect of a life form that could digest the very underpinning of
our existence? Only one sci fi example
exists, as far as we know, of such a threat to Earth’s minerals, the rather
far-fetched film Monolith Monsters,
in which alien crystals begin to grow disproportionately and dehydrate any
living things that come in contact with them.
Ironically, they are easily conquered when a dam is breached near a salt
flat and the flood of sodium chloride dissolves them into harmless sand. Yet this threat is literally superficial and
does not begin to approach the complexity of having to deal with a harmful
organism proliferating underneath the outer crust of the Earth.
So to
“get real” with this admittedly unusual sort of scenario, what could be
done? First, it seems prudent that a
containment area away from the Earth would be a good idea. The Moon might be a possible candidate, but
let’s not forget that, thanks to tides, the Moon is also an important part of
the Earth’s environment and may not make a good celestial guinea pig. Better would be a moon around the Moon, since
NASA is already proposing to tow an asteroid into lunar orbit as part of its
preparation for missions to the Asteroid Belt and Mars. Such an installation might cost more than one
on the lunar surface, but would add a useful degree of separation in a worst
case situation. Secondly, it would be
important to test possibly life-bearing samples not only in a vacuum, but in
simulated Earth-like conditions. If
earthbound industries and laboratories are the eventual destination, it follows
that we would have to be sure that organisms would not get out of hand if they
were exposed to oxygen, moisture, cosmic ray protection, and the other
privileges we enjoy. Lastly, some
consideration should be given to conducting materials processing at a location
above the Earth’s surface. This would be
enormously expensive in the beginning, but might actually pay for itself to
some degree by greatly reducing the mass of material that would have to be
moved from space to Earth, given the fact that navigating our atmosphere is the
most expensive and dangerous part of such transport. Ultimately, it may be impossible to completely
eliminate the danger of harmful exposure to organic life if we are determined
to travel beyond our present home. On
the other hand, failures like the Challenger disaster should convince us that
safety has to come first, especially on a planetary scale.
No comments:
Post a Comment