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Can Bacteria Survive Space Vacuum, UV?
Porfiry of ExoScience writes: "The theory that microbial life once came to Earth on a meteorite from another planet will be tested on July 26 when a NASA rocket carries into space special microorganisms from research at the University of Maryland Biotechnology Institute (UMBI). The tiny space pioneers will be riding an apogee, or suborbital, flight path similar to the historic 1961 flight of astronaut Alan Shepard. The passengers this time will be four dime-size cultures, each holding about 100 million cells of the microbes that will be exposed to space vacuum and solar radiation for 10 minutes."
One cannot prove that the universe was not created yesterday out of nothing, with all our memories and all its other internal records made consistent. On the other hand, such a theory has very little predictive power, since the next thing you look at might be the one thing that is not consistent. One cannot prove that the behaviour of gravity will not change tomorrow to cause the Earth to crash into the Sun.
Scientists always have to choose among the theories that fit the available evidence. Then they seek more evidence to test their choices. Experience leads to some "meta-theories" about which choices seem to work out better:
* simplicity -- once you have the right language (usually mathematics) then theories that derive lots of behaviours from a few simple rules seem to do well
* predictive value -- theories that don't let you make predictions about experiments not yet performed are not much use.
* mediocrity -- theories that have our location, our species or our epoch in the history of the universe as somehow special do not seem to do well
* aesthetics -- a bit of a two-edged sword, but brilliant and experienced scientists often seem to develop an effective intuition for which theories are "beautiful enough" to be true.
Anyway, returning to the question of evolution. All reasonably simple theories consistent with the biology that we observe seem to have
+ Mendelian inheritance, with minor modifications
+ Malthusian pressure resulting in not all
juvenile creatures actually breeding
+ mutations
A consequence of this is the sort of evolution by natural selection that can be seen going on over short timescales in (for instance) butterflies adjusting their camouflage to smoke polution, or cod breeding at younger ages under fishing pressure.
The next question is what happens if this process goes on over geological timescales (assuming for the moment the basic theories about the age of the Earth and the basic geological processes acting). Here, you will find more divergence among theorists about details, but most surviving theories do have species emerging, diverging and dying out, matching the fossil record. Recent theories suggest this may be less gradual and more jerky than earlier theories, with processes like the isolation of small populations on islands playing a larger role.
Finally, you can ask whether processes like these have been taking place in past, and if so, how the existing range of species fit in, which brings me back to where I came in: you cannot disprove creation yesterday, or one second ago. On the other hand, teh available records, mainly fossils, but also ice cores and other things, are really quite consistent with the broad thrust of evolution.
The near-Earth space environment is more complex than "gamma rays and a hard vacuum". There is the solar wind and solar radiation, cosmic rays, microgravity etc.
The experiment is a hitchhiker on a sounding rocket used for solar research, so it isn't costing the taxpayer big bucks.
Mea navis aericumbens anguillis abundat
I can imagine bacteria traveling through space, buried inside some porous rock... This way they don't have to be exposed to the harsh conditions of space.
-- Cheers!
Since then, theres been increasing scepticism over the bacteria. Since nobody expected to find any, no real precautions regarding sterility where taken with the handling of the camera and it's now thought the camera may have been contaminated on it's return. But nobody really knows for sure.
Does PETA know about this? Is there going to be a protest? How inhumane! Bacteria have a right to live just like we do. What's next? Monkeys? Dogs? People?!?
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'...let the rabbits wear glasses...'
Y2038 consulting
They have already found that these bacteria survive gamma rays and a hard vacuum in their lab.
Why should gamma rays and a hard vacuum be any more difficult to survive if it is in space?
Tarsnap: Online backups for the truly paranoid
will involve shooting politicians into space sans spacesuit, to see how well they stand up to the vacuum and solar radiation. Theorists propose that this form of life came to Earth from outer space, possibly on meteorites.
Gonzo
Today scientists dicovered several microscopic life forms living on a 5.25" disk containing the ancient classic Commander Keen. They are eager to investigate how the bacteria survived amid the piles of dust on the floppy.
Surviving in a hard vacuum and radiation is one thing, but surviving a re-entry into the Earth's atmosphere is quite another.
Not to mention the state the artifact must have been in when it was ejected from Mars in the first place. As I understand it, the theory is that significant meteor strikes on Mars can propel martian fragments outside of its gravity well. From all I've read about meteor strikes on Earth, any 'shrapnel' from a blast that large is molten rock when it ejects.
So the real question is: Can microbial life survive a molten host environment, then frozen, irradiated, and exposed to a hard vacuum (the microbes on the exterior, that is), then heated to near-molten levels again when it reenters the atmosphere? If so, we'd better not go to Io!
Kevin Fox
Kevin Fox
http://www.science.nasa.gov/newhome/headlines/ast0 1sep98_1.htm
Many have referred to it; here it is from a reliable source. Or as reliable as you get on the internet.
-Ben
I was briefly annoyed when I saw this article, but fortunately the scientists were smarter than the blurb made them sound. Of course throwing some random bacteria into space won't prove anything about the long-term space-endurance of their entire form of life. Bacteria, thanks to their rudimentary life-support needs and short generations, can undergo some truly striking mutations. The extremophiles are a group of bacteria that have evolved to live in ridiculously inhospitable extremes of heat, cold, and toxicity. Some species grow optimally at >100C and pH1.0 -- a hundred times more acidic than stomach acid and hot enough to boil water! In fact, the project appears to be using something similar, a bacterium which was discovered in an extremely hot geothermal spring.
Even then, Earth bacteria aren't necessarily going to have the right stuff. Bacteria that evolved on a planed without a magnetic field to block harmful high-energy particles and an ozone layer to absorb UV might have tolerances to radiation that would be stupidly excessive for anything in our relatively lax biosphere. Like bacteria from our own poles, life from a very cold planet might have a metabolism slow enough that traveling through space for 10,000 years wouldn't be a big problem (and if not, we always have spores). If you had some bacteria initially living on the interior of a chunk of ground that became a meteor, it's even conceivable that they could gradually evolve specifically to survive on the surface of a spacefaring rock.
If this fails, biologists might turn to trying to engineer bacteria that can survive in space. Creating selection pressure for radiation, vacuum, etc. isn't so hard...
- Michael Cohn
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Go ahead, blame me... I voted for Nader!