Author Topic: BFS quarantine ?  (Read 4670 times)

Offline Vultur

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Re: BFS quarantine ?
« Reply #20 on: 01/24/2018 04:41 AM »

The other way only if mars happens to have organisms. They might not be so friendly for us. Cause diseases etc that we might not be able to stop. Again, that assumes existing life on Mars.

Nah. Mars life would probably be killed by a human compatible environment. The metabolism and so on that's useful for being a chemosynthesizer in a sub-surface environment (any Mars life would probably have to be subsurface, both to have access to water and to survive high UV-C levels) aren't good preparation for surviving inside a human body. Miners in deep gold mines etc. don't worry about being infected with weird endolithic microbes, though those are known to exist and use our same basic biochemistry (RNA/DNA, protein

It's vaguely possible that Mars microbes or 'quasi life' [complex organic chemistry that doesn't really fit our definition of life] could cause allergic reactions or something, but contagious disease, no way. Contagious diseases are highly adapted to an environment that contains complex multi-cellular life to infect... Mars doesn't.

Offline SweetWater

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Re: BFS quarantine ?
« Reply #21 on: 01/24/2018 11:10 AM »
Sterile dirt? Or do you just want to waste money on a "perceived" safety procedure that really does nothing for safety?
First the scientists want to protect Mars from Earth. There are lots of earth organisms that could probably survive and form on mars. There are even organisms living deep in lava stone here on earth.

What the scientists fear is that if we 50 years from now find some organism on Mars, then the discussion would be if it really came from Earth with us and adapted to the environment. And that there never was life on mars until we came. Or if it's always been there. Then again, when we colonize mars there is probably no way to avoid contaminating mars.

The other way only if mars happens to have organisms. They might not be so friendly for us. Cause diseases etc that we might not be able to stop. Again, that assumes existing life on Mars.

I think the issue here is you are talking about trying to prove not one but two negatives.

The first is that any organisms we might potentially find on Mars did NOT have origins on Earth. As others have noted, there has already been - admittedly very limited - traffic of material and potentially microbes between the two planets in the form of meteorites. If microbial life is found on Mars 50 years from now, it will be very difficult to prove that it did NOT have its origins on Earth, whether from an meteorite from 10,000 years ago, the Mars 2 probe which crashed in 1971 or any of the probes and landers since, or from the first ITS landing, whenever that might be.

The second negative you are talking about trying to prove is that the first astronauts returning from Mars to Earth do NOT carry any disease or other harmful agents (ex: something like prions) with them. As others have noted, the return journey will take months, a period of time which would exceed even the most stringent quarantine requirements for any known disease/pathogen. Trying to prove that said astronauts are NOT harboring some unknown disease or other agent would mean an indefinite quarantine.

Offline Vultur

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Re: BFS quarantine ?
« Reply #22 on: 01/26/2018 06:18 AM »
If microbial life is found on Mars 50 years from now, it will be very difficult to prove that it did NOT have its origins on Earth, whether from an meteorite from 10,000 years ago, the Mars 2 probe which crashed in 1971 or any of the probes and landers since, or from the first ITS landing, whenever that might be.
Actually, it would be easily possible to tell if you had a sample of it.

If it doesn't have DNA/RNA, it's native.

If it does, but it doesn't fit on Earth's tree of life, it's either native or derived from meteor transfer very early in the solar system's history (before the most recent common ancestor of all current Earth life).

If it fits on Earth's tree of life, it's from Earth.

Offline jpo234

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Re: BFS quarantine ?
« Reply #23 on: 01/26/2018 07:56 AM »
If it does, but it doesn't fit on Earth's tree of life, it's either native or derived from meteor transfer very early in the solar system's history (before the most recent common ancestor of all current Earth life).

Or it's even older: https://en.wikipedia.org/wiki/Panspermia
« Last Edit: 01/26/2018 07:57 AM by jpo234 »
You want to be inspired by things. You want to wake up in the morning and think the future is going to be great. That's what being a spacefaring civilization is all about. It's about believing in the future and believing the future will be better than the past. And I can't think of anything more exciting than being out there among the stars.

Offline speedevil

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Re: BFS quarantine ?
« Reply #24 on: 01/26/2018 08:16 AM »

If it doesn't have DNA/RNA, it's native.

If it does, but it doesn't fit on Earth's tree of life, it's either native or derived from meteor transfer very early in the solar system's history (before the most recent common ancestor of all current Earth life).

'Native' DNA/RNA just isn't happening.
DNA/RNA is a very complex molecule, and there are many, many choices that are essentially random, but result in functionally identical molecules that vary significantly in all aspects.

As a rocketry analogy, it would not be at all surprising to find that other species developed chemical rockets that looked sort of like ours.
It would be very, very surprising indeed if they looked precisely like a Saturn V up to and including the paintjob.

Offline Vultur

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Re: BFS quarantine ?
« Reply #25 on: 01/26/2018 08:28 AM »

If it doesn't have DNA/RNA, it's native.

If it does, but it doesn't fit on Earth's tree of life, it's either native or derived from meteor transfer very early in the solar system's history (before the most recent common ancestor of all current Earth life).

'Native' DNA/RNA just isn't happening.


Maybe, but I don't think we know enough to say that yet -- we don't know what the earliest stages of life on Earth were. A lot of abiogenesis hypotheses involve earlier self-replicating systems that were replaced by the DNA/RNA/protein system -- I've even seen it suggested that TNA (threose nucleic acid, a simpler nucleic acid) might have predated RNA.

So if the evolution from another system to our current one was advantageous here, it might have been advantageous elsewhere too. We don't really know that there are "equally good" other systems.

Offline Athrithalix

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Re: BFS quarantine ?
« Reply #26 on: 01/26/2018 08:54 AM »
In terms of equally good other systems, we know of at least one. Biological molecules such as enzymes, nucleotides, and other proteins have a chirality, which means that they are one of two possible mirror images of that structure of atoms. Earth life all shares one chirality, as the opposite chirality is not compatible with our own. So even if our own forms of nucleaic acid turn out to be the only viable ones for life (which would surprise me), there are still at least two different forms for it to fit. Martian life found with DNA but opposing chirality would be really weird, it would be obviously not Earth originating, but also tell us a huge amount about how narrow the path is for biogenesis, but also that that narrow path is stunningly common enough and easily followed to generate life on two different planets within one solar system.

Offline Vultur

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Re: BFS quarantine ?
« Reply #27 on: 01/26/2018 09:16 AM »
Yeah, reverse chirality is another possible variation.

I'm not saying independent origin of DNA/RNA is necessarily likely (I don't think we know enough about the early steps in the origin of life to say either way).

 I was just trying to cover all bases - my point was that even an independent origin of Earth-type biochemistry (DNA/RNA/protein) would be distinguishable from "recent" (post-Late Heavy Bombardment or thereabouts) Earth contamination, since its DNA sequence wouldn't fit on the Earth tree of life.


Offline Katana

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Re: BFS quarantine ?
« Reply #28 on: 01/26/2018 01:58 PM »
I agree. I'm not a chemist or a biologist but I'd assume that any martian superbug seeking to do us harm would have to:

1.  ...have the same biology as human(earth) biology - very unlikely unless it evolved on earth.
2.  ...be able to interact with our biology. If it evolved with different biology, then to them humans might as well be dead rocks.
3.  ...want to feed on us. - Again, If it evolved with different biology, then it'd be like impala trying to feed on meat.

Or just simply be like any microbe taken from the desert and dropped in the ocean - out-competed in seconds by the locals. Microbes develop in particular niches and are in constant competition with other microbes. The idea that some introduced interloper is going to somehow instantly be top dog is silly.

And that's the most plausible scenario... the science fiction scenario is that somehow a Mars microbe is a human pathogen, how's that work? The vast vast vast vast (I could go on, Douglas Adams style) majority of microbes on Earth don't have any effect on us - you can inject them into your bloodstream and not have a problem - the minuscule number that are a problem for us have co-evolved with us and other animals on this planet. It's simply impossible for a microbe from Mars to have a deleterious effect on humans.

NASA's planetary protection position is simply junk science. It's outdated claptrap.
Protests of public environmentalists may become bigger problem than NASA's planetary protection.
Compare to GM crops (food safty) and LHC accelerator ("hazard of artificial black hole").

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