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Cosmonaut Anton Shkaplerov suspects an extraterrestrial origin for bacteria found on the exterior of the ISS:
A Russian cosmonaut claims to have caught aliens. Cosmonaut Anton Shkaplerov says he found bacteria clinging to the external surface of the International Space Station that didn't come from the surface of Earth.
Shkaplerov told the Russian news agency that cosmonauts collected the bacteria by swabbing the outside of the space station during space walks years ago.
"And now it turns out that somehow these swabs reveal bacteria that were absent during the launch of the ISS module," Shkapkerov told TASS. "That is, they have come from outer space and settled along the external surface. They are being studied so far and it seems that they pose no danger."
A recent study suggests that interplanetary dust can transport microbes to or from Earth:
Astronomers have long believed that asteroid (or comet) impacts were the only natural way to transport life between planets. However, a new study published November 6 in Astrobiology suggests otherwise.
The study, authored by Professor Arjun Berera from the University of Edinburgh's School of Physics and Astronomy, suggests that life on Earth may have begun when fast-moving streams of space dust carried microscopic organisms to our planet. Berera found that these streams of interplanetary dust are not only capable of transporting particles to Earth, but also from it.
Space Dust Collisions as a Planetary Escape Mechanism (DOI: 10.1089/ast.2017.1662) (DX) (arXiv link above)
(Score: 5, Interesting) by takyon on Wednesday November 29 2017, @10:32AM (9 children)
How about a dedicated sterilized satellite in Earth orbit, intended solely to collect and analyze anything that hits it.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 5, Informative) by Anonymous Coward on Wednesday November 29 2017, @10:55AM (8 children)
The point is that you can never be sure that the thing is 100% sterile.
This news makes me as a biologist very sceptical. The fact that you found bacteria on the exterior of the ISS, which weren't present during launch, isn't proof on itself.
There could be dozens of ways for the bacteria to get there (and evolved), from the earth afterwards. But even if we would find "extraterrestrial/alien bacteria", it could
actually be pretty hard to proof that it would be alien (even more if it remotely contains similar building blocks as those found on the earth).
Let's say you would have the following classes:
1 Earth bacteria
2 Earth bacteria "adapted to space", which look somewhat alien
3 Alien bacteria that contain similar building blocks as 1 or 2
4 Alien bacteria, that don't share any similarities with 1, 2 and 3
Everyone expects that we would get 4, which would be the easiest to identify (but earth could be lethal to them or very hard to grow in laboratory conditions), but 3 is
more likely as (bio)chemistry is limited by it's physical properties. How would be proof that 3 is different from 1 or 2? There would be a few leads, but even if they fail
you could en up with an alien bacteria that you can't be fully sure it's alien.
(Score: -1, Troll) by Anonymous Coward on Wednesday November 29 2017, @11:21AM
Just import your alien life forms from Mexico. Why you gotta make thing so complicated?
(Score: 2) by sgleysti on Wednesday November 29 2017, @04:08PM
It could be bacteria we were unable to detect when launching the parts of the ISS but are able to detect now with better or different tests.
It could be bacteria that migrated from the inside to the outside of the ISS.
It could be bacteria that traveled from the upper atmosphere of earth to the ISS. Another commenter mentioned this, and I think it's brilliant. We know there are many species of bacteria that we know next to nothing about because we can't grow them in the lab, but we can see their DNA fragments in soil samples, etc.
(Score: 3, Interesting) by Immerman on Wednesday November 29 2017, @04:20PM (4 children)
Any life that arose independently from that on Earth would almost certainly be composed of different amino acids (since there doesn't appear to be any particular advantage to the ones we utilize). To say nothing of having evolved different information-storing molecules, organelles, etc. Life is actually pretty inefficient since natural selection makes it extremely difficult to escape from local maximums. Basically, if it's similar enough to be honestly classified as a bacteria, it almost certainly shares common ancestry with Earth life.
Of course that doesn't rule out an extraterrestrial origin - the particular species may have originated on Earth and then spent millenia evolving elsewhere before chance brought it back here. Or Earth life itself may have originated elsewhere - for example Mars was potentially a lush Earthlike world long before Earth cooled enough to form oceans - and life-bearing Mars debris cluttering the solar system would certainly explain the fact that life appears to have been present on Earth from almost the moment it cooled enough to form oceans.
Assuming it is a bacteria, sharing common ancestry with Earth bacteria, given the mind-boggling variety of life on Earth it might be a real challenge to determine whether a newly discovered bacteria species actually originated here or not. Heck, the broad-spectrum DNA sequencing of sea-water suggests that something like 20% of species on Earth are some form of life whose very existence we never even previously suspected.
(Score: 2, Informative) by Crash on Wednesday November 29 2017, @08:28PM (3 children)
(Score: 3, Informative) by Immerman on Wednesday November 29 2017, @08:43PM (2 children)
What does speed of evolution have to do with the efficiency of the results?
Some things (body shapes and surfaces of swimming animals) are relatively easily optimized. Many others, like photosynthesis, are prone to local maximums - most plant photosynthesis is between 0.1% and 2% efficient at converting available photons to chemical energy. https://en.wikipedia.org/wiki/Photosynthetic_efficiency [wikipedia.org]
(Score: 1) by Crash on Thursday November 30 2017, @05:29AM (1 child)
Well life is change. Without change there is not life. Evolutionary change has long been theorized to be on a geological time-scale. Yet we are finding evidence that that may not be the case.
Further, I don't see how stating some low value for the "efficiency of photosynthesis" as a proof of anything, let alone a proof that life is inefficient.
Why would plants generate more energy than they need?
(Score: 3, Informative) by Immerman on Thursday November 30 2017, @06:49AM
Certainly change (and thus evolution) is inherent in life as we know it, and I've never heard anyone make the claim that it only happens on geologic timescales - it happens in tiny increments with every birth and every death. But evolution just causes change - on its own it's extremely unlikely to cause two unrelated species to have any substantial similarities to each other.
Efficiency matters because that's what drives convergent evolution - sharks and dolphins have extremely similar body shapes because that is a fairly optimal shape for animals that need to travel quickly through the water - physics guides two completely different species to the same basic conclusion because it's an extremely efficient design. Photosynthesis on the other hand is nowhere remotely close to an optimally efficient design, and so if we find alien "plants" that use photosynthesis we'd expect them to use some other mechanism to perform the same basic function - efficiency would not guide a different species to find the same solution.
And efficiency matters because it increases your ability to survive and prosper, which is the driving force behind natural selection. Start with two almost identical seeds planted side by side, the only difference being that one has a mutation that makes it twice as efficient at photosynthesis. That difference means that from the moment they push their first leaf into the sun, the mutant is collecting twice as much energy from the sun as its twin. That means it can grow its leaves faster, absorbing even more sunlight, and grow its roots faster, absorbing more water an nutrients from the soil. And the bigger and faster it grows, the fewer resources are available to its twin. Even if the twin doesn't get starved out entirely, the mutant will be able to afford to produce a lot more seeds, and all the offspring that inherit its mutation will have a similar advantage - after a thousand generations there probably won't be any of the original non-mutant plant left - it will either have been outcompeted into extinction, or have developed new mutations that give it an advantage in some other way, possibly even letting it migrate into an ecosystem where the original mutants can't survive to compete in the first place.
(Score: 3, Interesting) by HiThere on Wednesday November 29 2017, @05:50PM
Considering that they have divided the Earth-native bacteria into separate kingdoms which branched apart during the Cambrian (the Precambrian?), I would expect that a genetic analysis of any alien bacteria to reveal at minimum that they weren't a member of any existing kingdom of life. This might not be literal proof that they were alien, but would be an extremely good signal.
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