Bacteria survival in the vacuum of space

Reproduced from panspermia.org by Brig Klyce

"I always thought the most significant thing we found on the whole damn Moon was the little bacteria that came back and lived and no one was saying shit about that." - Pete Conrad

"On April 20, 1967, the Surveyor 3 unmanned lunar module landed near Oceanus Procellarum on the surface of the moon. One of the instruments on board was a television camera. Two and a half years later, on November 20 In 1969, Apollo 12 astronauts Pete Conrad and Alan L. Bean recovered the camera.When NASA scientists examined it again on Earth they were surprised to find samples of Streptococcus mitis that were still alive. Due to the precautions they had put in place. taken by the astronauts, NASA determined that the germs were inside the chamber when it was recovered, so they must have been there before launching Surveyor 3. Apparently, these bacteria had survived for 31 months in the vacuum of the atmosphere of the Moon. Perhaps NASA shouldn't have been surprised because there are other bacteria that thrive at very low pressures on 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? Bacteria in the recovered chamber from the Moon would have suffered enormous monthly temperature swings and a complete lack of water. Freezing and drying, in the presence of the proper protectors, are actually two ways that normal bacteria can enter a state of suspended animation. And, interestingly, if the correct protectors are not supplied originally, the bacteria that die first supply elements for the benefit of the survivors! English microbiologist John Postgate discusses this fact in The Outer Reaches of Life

When a population of bacteria dries up without a protector, many of the cells break open and release their inner contents. These include proteins, gums, and sugars, all of which are protective. If the population is dense enough that significant amounts of protector are released, the material released from the majority who died first may protect some of their fellow survivors.

"Comparable considerations apply to death by 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 many substances that are cryoprotective. ".

Postgate says that the bacteria have apparently survived for 4,800 years in the brick of Peruvian pyramids, and perhaps even 300 million years in coal, using the drying strategy. It 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 the nutrients available in the carcass. Postgate gives several other examples of long-surviving bacteria, and is careful to mention the possibility that some of the bacterial cultures have been contaminated, so not all reports are necessarily reliable.

Some bacteria have an even more efficient survival strategy: they form spores. Spores are fully dormant bacterial cells with thick protective layers. In terms of our computer analogy, a bacterial spore is like a handheld calculator that has been repackaged in its original protective cardboard and turned off.

"The resistance of some bacterial cells to the destruction of the environment is impressive. Some bacteria form resistant cells called endospores. The original cell replicates its chromosome and one copy is surrounded by a resistant wall. The outside of the cell disintegrates, but the endospore contains survives all kinds of trauma, such as 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 period of time .... Endospores can remain dormant for centuries. "

Postgate concludes his chapter on spores, entitled "Immortality and the Big Sleep," by saying, "There may be many older spores out there, waiting for energetic microbiologists to revive them." And indeed there are.