How An Andromeda Strain Might be Strained

An anonymous reader writes "For the world-record holder as the longest surviving bacteria in space [6 years, Bacillus subtillis], it turns out that among the multitude of dangers [cold, vacuum, UV, lack of nutrients, etc.] the greatest stress of all is intense ultraviolet radiation. In the next two years, new space station experiments are slated to test the panspermia hypothesis--also popularized in Robert Zubrin's "Entering Space", but dating back at least 150 years in the scientific literature. Recent balloon experiments, have rekindled alot of the controversy, but NASA Ames scientist, Rocco Mancinelli, concludes: "In my opinion, for a spore, it's quite likely.""

Comments

Why is this a surprise?

[slycer9]

It's been a long standing standard that one of the most effective antibacterial/antiviral measures one can take today is UV irradiation, it's one of the few things most movies even get correct. Hell, even most of the studies done about UV irradiation on humans in space is inconclusive. Or has all the hype in the past (Anti-Anthrax measures in post offices) been just optimistic public placating?

Re:Why is this a surprise?

[The Original Yama]

You just need to make sure you've killed EVERYTHING. Otherwise, if given enough time, the bacteria may develop a resistance through evolution. Apparently there was bacteria on the Mir space station that had evolved (due to the pressures of the environment, etc.) to the point where it could eat through titanium. Of course, this caused all sorts of damage to space station components. The ISS may breed similar kinds of life. Recent measurements have shown that ISS occupants receive the same level of radiation in a day as a human on earth receives in a whole year.

Re:Why is this a surprise?

[Strange Ranger]

An interesting (and slightly worrisome) aspect of this is that most radiation, including UV, is known to greatly increase the number and degree of mutations over time.

Not only does it select for a trait (UV immunity), it causes lots of mutations. Sort of a synergistic Darwinism. Combined with other techniques - What a great way to create nifty new bacteria. Neat, and of course a bit scary.

Lunar Colonists Were Returned To Earth...

[cybrpnk2]

Another prime example of bacterial space survival was found by Apollo 12 when it brought back parts of the unmanned Surveyor 3. Conrad's quote here has been censored, incidentally; his original quote was a little pithier...

Bacteria on the moon

[jeff_bond]

An interesting link about bacteria that was unintentionally left on the moon, and was later brought back to earth alive.

Jeff

Hostile space environment

[panurge]

Ever since thiobacter concretivorans was discovered chewing its way through concrete in nuclear reactors, we've known that life is not necessarily restricted to a temperature range of around 0-40C. (That's 32-104F for people who hate the French.) What with the stuff that grows in hot springs at 95C (work out yourselves), and the stuff that lives at the bottom of oceans, we shouldn't really be surprised if microorganisms can survive in space - after all, comets have plenty of ice and dirt, just like the Earth. And no matter how bad the UV, there is going to be somewhere on a comet or small asteroid that is shaded from direct solar radiation. Maybe I'm just being stupid, but to me the argument goes something like (and I may be repeating myself, if so sorry)

50% of the planets we've actually checked out are inhabited.

The other 50% have been visited by human beings who have left artefacts behind

So why do we expect the rest of the universe, including the non-large rocky bits,to be life-free?

Re:Hostile space environment

[CommieLib]

I've heard this argument quite a bit over the years and while it certainly is true that life can survive in extremely hostile conditions, it does not necessarily stand to reason that life could develop equally well in such conditions.

Colder conditions are necessarily going to have fewer of the chemical reactions that lead to the bottom of the chain that is life. Hotter conditions are likely to have so much entropy that life either never develops initially or is wiped out over and over again.

The whole question, however, may be moot. As Zubrin points out in Entering Space, Earth-originating bacteria has possibly already reached other star systems. So as the unmitigated greatness of Red Dwarf posits, it's possible that life evolves nowhere else in the universe than Earth and things are still pretty interesting.

I'd like to know...

[GeckoFood]

...is how said information would be useful to us, since we already know what stresses bacteria. I mean, are we looking for an advancement in medicine or something, that will, say, extend the shelf life of certain helpful cultures or anything like that? Or is this just for the pure science of it and the satisfation of having knowledge?

I don't care either way. It's interesting to follow stuff like this, but it makes it a lot more interesting for the spectator when one knows what the goal is...

Re:I'd like to know...

[Daniel Dvorkin]

Right now, the goal is just to know. That's it.

Eventually ... who the hell knows? We may learn something that will have direct medical applications. Or we just have more data to file away in the ever-increasing store of human knowledge, and a century or three from now someone will come along and say, "Hey, I can use this."

I'm all for applied scientific research (I ought to be, considering I work in biotech.) I'm also all for pure scientific research, since, a) more knowledge is never a bad thing -- yes, I will happily defend that statement against the "things man was not meant to know" crowd -- and b) most of the useful technology we have today was based on what was, at one time, pure science without any obvious application.

Benjamin Franklin watched the Montgolfier brothers' first balloon go up. When someone else asked him of what use he thought such a thing might be, he replied, "Of what possible use, sir, is a new-born babe?" Exactly.

Guess they haven't tested this one

[Anonymous Coward]

"Deinococcus radiodurans is the most radiation-resistant organism known. Deinococcus radiodurans were discovered in 1956 by Arthur W. Anderson at Oregon Agricultural Experiment Station in Corvallis. Among the many characteristics of Deinococcus radiodurans, a few of the most noteworthy include an extreme resistance to genotoxic chemicals, oxidative damage, high levels of ionizing and ultraviolet radiation, and dehydration. "
- http://deinococcus.allbio.org/

Re:life finds a way

[Angry White Guy]

The interesting side effect of this could be the ability to terraform worlds using re-engineered bacteria. Get those suckers breathing in toxic fumes, breathing out the building blocks for human life, and infect millions of worlds.

Re:Question...

[Andrewkov]

Seems unlikely to me. Virus and bacteria evolved over millions of years to be compatible with animals and people on our planet. I don't think we'd make good hosts for a parasite that had evolved on another planet. At least I hope not!! ;-)

I Wish!

[deathcloset]

what are the chances of a planet like earth with a star like the earths with the chemical makeup of earth getting hit with a comet/big-ass-thing (probably the most likely part of the equation), which is not so terribly big as to wrend the planet into star-orbiting dust, and not too small as to allow the pieces to coalesce back into a nice spheroid, but just big enough to launch a healthy piece (meaning lively) through space to rendevous with a planet like earth with a star.......you get the picture.
I want just as badly as any other sci-fi buff to make it with a hot alien babe. But let's face it. 2 meter tall, bipeadal, sexy aliens are pretty unlikely...Even more unlikely than life as we know it or most of us getting laid tommorow.
"We have calculated (in the Mileikowsky paper in Icarus (2000) that in order to protect spores for 1 million years against cosmic radiation, a 1-meter-thick layer of the meteorite is necessary." ...how thick must it be for entry through an atmosphere?

About Mars and dark sands

[Ektanoor]

Well this is not exactly about panspermias but it may be an interesting note about the possibility of life in outter Space.

I would risk to say that we may already have some evidence (not proof!) that something alive may thrive in Mars surface. Nearly two years ago I got hand in a frame where one could see both light and dark dunes among a rugged Mars landscape. It was interesting to note that dark dunes formed mostly opposite to the general pattern of winblow that could be inferred from light dunes and the erosive processes in mounds and cliffs. Besides, on several places, under certain mounds, one could see how "dark sands" covered one side in a weird manner. They would concentrate over the base of the mound's side and swiftly dissipate the farer they would be from the mound.

MSS scientist claimed that these pattern was the result of light dunes being "pertified" and that dark dunes being "active". However, in several places, one could be pretty sure that the light mounds were still very active, was they "cut" a dark dune with their edges. Moreover, in one section of this regon, dark dunes would always "hide" behind the bigger and larger light dunes.

In the whole, it seemed that dark dunes ran away from light and wind, what was quite weird. As the region presented lots of data on how wind acted, the pattern was clear and perfect.

On other section of Mars I saw an even more weird picture. There, dunes would have clear and well visible "bridges" between themselves - patches that united dunes well far away from each other. In one place, such "bridge" was rising over a mound, going down through a small cliff and uniting two dark dunes quite far apart from each other (maybe more than a few hundreds of meters).

These strange and weird dark dunes are a mistery in Mars, many of them are clear and pure dunes, only its dark pattern gets quite weird as they don't have a clear origin. However some places show dunes that are only slightly similar to natural dunes. They are more compact, smaller than light dunes, Besides they present a "water drop" pattern rather than presenting the usual crescent shape of most dunes.

This is not the only weird thing in Mars about "dark lands" There are many more. However this is the most widespread weird feature in the planet. One can see this from pole to pole. However they are not in every place. They are quite localized in certain regions, while others lack them completely.

Don't forget abiogenesis

[job0]

The hypotheses competing with panspermia is abiogenesis. Abiogeneis theorises that life can arise spontaneously from non-life molecules under proper conditions. I tend to favour abiogeneis slightly over panspermia simply because we know
that there is life on Earth, but we don't know if there is any elsewhere in the Universe.

The four steps to necessary for Abiogenesis are:

Inorganic Molecules to Organic Monomers

Organic Monomers to Organic Polymers

Formation of membranes from the polymers

Acquisition of a means of reproduction

Maybe the asteroids instead of seeding the earth provided the energy required for the first step.

Re:Don't forget abiogenesis

[CowbertPrime]

However, astronomers have shown that dust particles near UV radiation (e.g. near a star) can form organic monomers from diatomic molecules, such as raw carbon, H2, and O2, because intense UV forms radicals that quickly react with the native species to form such compounds as glycine and acetate.

Furthermore, the Urey-Miller experiments have been recently underplayed because it has been determined that the early Earth atmosphere did not contain high concentrations of methane and some other compounds that Urey-Miller used as the assumptions for that experiment.

Abiogenesis seems to be more logically sound than panspermia because as you say, we have no proof of life elsewhere in the universe, so panspermia ultimately still begs the question of 'who was first'. However, abiogenesis has its own issues with inflation (saying that impossible odds can be overcome by postulating an undefined but presumably infinitely large population - if the chance for a reaction involving 2 species is 1E-24, then we postulate that there were more than 2E24 particles in the same volume and that the 2 particular species were close enough to react. It is not merely the inflation of numbers, but inflation of the probability that the two particles are in the same vicinity).

Re:UV Radiation

[CowbertPrime]

Most space 'surviving' organisms do just that. They 'survive'. They lie dormant and shield their DNA using spores or some other sort of mechanism. In any event, they don't have high metabolic rates (that would induce the creation of more oxidants and radicals) and don't divide, as DNA polymerase is very picky about structural morphology and damage such as mismatches or crosslinking will cause polymerase to stall, fall off, or skip the section - it is these times where reproduction of bad DNA becomes fatal. Lysogenic phages also react to UV damaged DNA and excise themselves, enter the lytic cycle and further contributes to cell death.

However, low dose UV mutagenesis is used quite often, because interesting things happen when bacteria are exposed to UV. Bacteria do have sets of genes that repair UV damaged DNA, in addition to the so-called SOS response. Most UV damage occurs is not directly detrimental - just the formation of pyrimadine dimers which kinks the DNA and either prevents transcription or replication. The uvr (UV Repair) genes along with umu (UV Immutable) genes can do nifty things like replace the beta subunits in polymerase to accomodate structural defects, meanwhile. Prokaryotes even have phr (Photo Repair) systems to fix this stuff using longer wavelength light. Where large sections of DNA are skipped during replication, recombination can be used as a repair mechanism. At least these can keep the cell alive, but incur lots of mutations, which is useful when you are not sure what kind of mutation you are looking for and you don't know the locus so that chemical mutagens are ruled out in addition to site-directed mutagenesis.