Survival of bacteria in the space vacuum
Reproduced from panspermia.org
by Brig Klyce
I always thought the most significant thing that we ever found on the whole goddamn Moon was that little bacteria who came back and lived and nobody ever said shit about it. — Pete Conrad
"On April 20, 1967,
the unmanned lunar lander Surveyor 3 landed near Oceanus Procellarum on the
surface of the moon. One of the things aboard was a television camera.
Two-and-a-half years later, on November 20, 1969, Apollo 12 astronauts Pete
Conrad and Alan L. Bean recovered the camera. When NASA scientists examined it
back on Earth they were surprised to find specimens of Streptococcus
mitis that were still alive. Because of the precautions the astronauts
had taken, NASA determined that the germs were inside the camera when it was
retrieved, so they must have been there before the Surveyor 3 was launched.
Apparently, these bacteria had survived for 31 months in the vacuum of the
moon's atmosphere. Perhaps NASA shouldn't have been surprised, because there
are other bacteria that thrive under near-vacuum pressure on the earth today.
Anyway, we now know that the vacuum of space is not a fatal problem for
bacteria.
What about the low temperature and the possible lack
of liquid water in space? The bacteria in the camera recovered from the moon
would have suffered huge monthly temperature swings and the complete lack of
water. Freezing and drying, in the presence of the right protectants, are
actually two ways normal bacteria can enter a state of suspended animation. And
interestingly, if the right protectants aren't supplied originally, the
bacteria that die first supply them for the benefit of the surviving ones!
English microbiologist John Postgate discusses this fact in The Outer
Reaches of Life
When a
population of bacteria dries out without a protectant, many of the cells break
open and release their internal contents. Among these contents are proteins,
gums and sugars, all of which are protective. If the population is sufficiently
dense, so that significant amounts of protectant are released, material
released from the majority which died first can protect a few of their
surviving fellows.
"Comparable considerations apply to death from freezing....
Protective substances such as glycerol are well known and widely used; they are
called cryoprotectants. Bacteria frozen without such chemicals leak internal
contents, among which are many substances that are cryoprotective."
Postgate says that bacteria have apparently survived for 4,800 years in
the brickwork of Peruvian pyramids, and maybe even 300 million years in coal,
using the drying strategy. He also describes bacteria that apparently survived
for 11,000 years in the gut of a well-preserved mastodon, although in this case
the colony may have continued to live and multiply using nutrients available in
the carcass. Postgate gives several other examples of long-surviving bacteria,
and he is careful to mention the possibility that some of the bacterial
cultures may have been contaminated, so not all of the reports are necessarily
reliable.
Some bacteria have another even more effective survival strategy: they
form spores. Spores are bacterial cells in complete dormancy, with thick
protective coats. In terms of our computer analogy, a bacterial spore is like a
handheld calculator that has repackaged itself into its original protective
shipping carton and turned itself off.
"The resistance of some bacterial cells to
environmental destruction is impressive. Some bacteria form resistant cells
called endospores. The original cell replicates its chromosome, and one copy
becomes surrounded by a durable wall. The outer cell disintegrates, but the
endospore it contains survives all sorts of trauma, including lack of nutrients
and water, extreme heat or cold, and most poisons. Unfortunately, boiling water
is not hot enough to kill most endospores in a reasonable length of time....
Endospores may remain dormant for centuries".
Postgate concludes his chapter on spores, entitled "Immortality and
the Big Sleep," by saying, "There may be much older spores out there,
waiting for energetic microbiologists to revive them." And there were.
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