Slashdot Mirror
Bacteria Found On ISS May Be Alien In Origin, Says Cosmonaut (independent.co.uk)
Kekke writes: Lots of buzz around this. Russian cosmonaut Anton Shkaplerov took routine samples from the outside of the International Space Station during a spacewalk. These samples were analyzed and found to contain bacteria that must have come from somewhere other than Earth or the ISS itself. "Bacteria that had not been there during the launch of the ISS module were found on the swabs," Mr. Shkaplerov told TASS Russian News Agency. "So they have flown from somewhere in space and settled on the outside hull." He made it clear that "it seems, there is no danger," and that scientists are doing more work to find out what they are. The Independent writes, "Finding bacteria that came from somewhere other than Earth would be one of the biggest breakthroughs in the history of science -- but much more must be done before such a claim is made."
The claims of alien bacteria on the ISS are being met with widespread skepticism.
ISS har for 20 years been orbiting - a close distance - around a planet with gazillions bacteria an microbes, and been visited by more than a hundred people, and it was lanuched through the atmosphere containing lots of microscopic life, and as soon as bacteria is found on the outside, it is considered likely to be of alien origin?
Gimme a break!
I would be very surprised if we could keep it completely clean from earthly contaimination, even if we are talking about the outside.
So while it's likely that life is based on DNA elsewhere in the universe
We don't have sufficient data to claim that it's likely. We only have a single data point, and very little understanding of the mechanism that led to evolution of DNA.
A few years ago there was a woman in Germany that seemed to have been involved in all kinds of spectacular crimes, mostly murder. Her DNA was found on various crime scenes that seemed totally unrelated, She must have been the most wanted criminal for a while and was called the "Phantom". There was a $400,000 reward put on her head
Of course it turned out in a slightly different way than police had expected. The DNA that was found was actually from a female factory worker packaging the cotton swabs that were used by German police to collect DNA, so these DNA traces were simply a contamination. Here is the whole story: http://content.time.com/time/w...
You can expect something similar from the bacteria on the ISS. Everybody of course wants some spectacular news, but unfortunately there are far more mundane ways how the bacteria could have ended up there.
Signature deleted by lameness filter.
Agreed. Imagine you have an 8 inch volleyball, drenched with syrup. A quarter of an inch away, almost touching the syrup-coated volleyball, there is a coin and you find microscopic traces of syrup on the coin. How do you guess the trace of a syrup got on the coin?
Most likely, it came from the big ball of syrup right next to the coin. Or maybe somehow syrup came in from outside and got on the coin, without ever making it 1/4 inch further to get in the volleyball. Which seems most plausible?
That's the scale we're talking about with ISS. Earth is 8,000 miles diameter, 25,000 miles circumference. The atmosphere extends to 6,200 miles up (exosphere). ISS is below the exosphere, in the thermosphere. ISS is only 250 from the surface - nearly touching the ground.
As someone else hinted, IIS is also travelling 18,000 miles per hour. At that altitude, there are roughly 4,000,000,000 air molecules per cubic meter*. Meaning ISS is colliding with billions of air molecules per second. It would be surprising if they didn't get a bug on the windshield.
* Yeah I used imperial and metric in the same post. Get over it.
There are plenty of native bacteria that won't grow in culture, and one reason archaea took so long to elucidate is that it is hard to use PCR on "unknowns." Since we wouldn't have primers for an alien bacterium (and really no reason to expect it to be using DNA or RNA at all, unless panspermia is correct and it has common ancestry with us) we'd mostly have to be lucky that it was able to be cultured. It'll be a while before we can find truly alien microbes with any ease.
Actually, the chance of some other life form not using DNA/RNA is very very low. Carbon based organic molecules and amino acids have been found pretty much everywhere we have looked including interstellar gas clouds. They're all over the place. And RNA is about as basic as you can get for consistent replication molecule.
Now hypothetically any other "sticky" atom could be a basis for organic type chemistry (like silicon) but they are all less likely due to the difficulty of the chemistry. It COULD happen under the right circumstances, but we don't see the silicon equivalent of amino acids on comets or in interstellar gas clouds.
Back to this story, it is unlikely that these organism are extra-terrestrial. There are any number of ways terrestrial bacteria could have found there way up there. It's a bold and foolish claim that they would be from elsewhere without hard evidence.
~X~