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Who is the caretaker of martian life?


PB666

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Very interressing, thanks.

So, will the rover Curiosity be allowed to inspect the nears "wet slopes" or not? ^^

Curiosity has a limited amount of travel distance left in the wheels, if they do anything it will probably be after all other targets have been reached. I suspect tgat will give them enough travel time on the surface to purge all terran microbes from the rover.

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Curiosity has a limited amount of travel distance left in the wheels, if they do anything it will probably be after all other targets have been reached. I suspect tgat will give them enough travel time on the surface to purge all terran microbes from the rover.

Look like a good compromise. Thanks.

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A side note: idealy, you would be here to see the "wet slopes" at the peak of local summer, because it's the only time in the martian year they actually flow.

The actual summer mars solstice is for January 2016: we are actually at the start of the martian summer season.

http://www.planetary.org/explore/space-topics/mars/mars-calendar.html

The next summer mars solstice is for november 2017.

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I have a question

If there is remaining alive spores on a martian rover, any rover.

Would'nt theses spores alway got a chance to be everywhere on Mars, and not only lying on the ground on the rover tracks?

Mars has a, active atmospher, with hurricanes winds that can make global planetary dust storms:

20100813142924-cb3908d8.jpg

So, any spore left by any rover could already have been carried anywhere on Mars, no?

Edited by baggers
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I have a question

If there is remaining alive spores on a martian rover, any rover.

Would'nt theses spores alway got a chance to be everywhere on Mars, and not only lying on the ground on the rover tracks?

Mars has a, active atmospher, with hurricanes winds that can make global planetary dust storms:

http://orbitmars.futura-sciences.com/galerie_images/upload/2010/08/13/20100813142924-cb3908d8.jpg

So, any spore left by any rover could already have been carried anywhere on Mars, no?

Just because it could have happened doesn't mean we can just throw caution to the wind and make it actually happen.

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Interesting concept, once you really start thinking about it.. Clearly, the norm in human history has been to exploit and demolish whatever natural habitats we encounter. This occurs even when the intrusion is done with the best of intent (which is rare).

Suppose we go to great lengths to avoid contamination, and then find alien bacteria on Mars. This implies that alien bacteria is very, very common in the universe. Do we now disregard it and terraform the planet? If we do not find alien life, how long do we wait to be sure, before terraforming?

Is it unethical to ever terraform, because the possibility exists of life developing there on its own at some point in the future?

There is no end to the questions that we should be debating and answering right now. Unfortunately, I see no such debate happening anytime soon (ever) in the public sphere..

How do you know that we don't bring the lifeform back to earth and the destroy complex life here on Earth?

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As I have mentioned, any water-based life on Mars is very likely to have a common origin with that of Earth. This nullifies the "common" argument for life. It's been estimated that two percent of fragments from Earth impacts end up on Mars, and some bacteria can survive in space for a while.

Edited by Findthepin1
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That is astronomically unlikely :D

Such an organism would have to be able to survive on the alien habitat, through the space journey and thrive on earth in all of our different environments and be evolved in just such a way to be fatal to all of our different forms of life and be able to overcome the human immune system, antibiotics, and any adaptation that we could make as it spread.

Basically, if the variety of earth-bound viruses and germs can't kill us all, then a few alien ones won't either.

It could come back as soil loosened and collected on our return craft, the nematodes after survived the last space shuttle disaster, including the reentry part. Bacterial spores might have an easier global re-entry.

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But most of our asteroids that went to mars were from the early bombardment, can we name an asteroid that hit earth since complex life developed that had sufficient energy for an eject path to mars. Just survivng the drag of our atmosphere has a pretty good effect on dV, then getting past the moon and several passes of earth before finnaly being steered into mars. Tge mars fragments appeared to have reached earth, but they may be billions of years old and life that was not as well developed.

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If we do not find alien life, how long do we wait to be sure, before terraforming?

Is it unethical to ever terraform, because the possibility exists of life developing there on its own at some point in the future?

I see very little value in even attempting to terraform Mars. I suspect any reasonable candidate for terraforming will already host alien life.

Thus I consider the question to probably be irrelevant.

How do you know that we don't bring the lifeform back to earth and the destroy complex life here on Earth?

And how do we know the universe won't implode due to a mteastability event:

https://en.wikipedia.org/wiki/False_vacuum#Vacuum_metastability_event

It seems extremely unlikely that anything from mars could survive and outcompete native Earth life, unless it shares a common ancestor with Earth life, in which case, it wouldn't be such a big deal.

As I have mentioned, any water-based life on Mars is very likely to have a common origin with that of Earth. This nullifies the "common" argument for life.

That doesn't nullify anything, especially if it didn't actually share a common origin.

I think people are way to optimistic about a bacteria surviving an ejection by a meteor, the trip through space, the landing, and then *most of all* being anywhere close to suited to the environment it finds itself in.

We often think of microbes as quite hardy, but many won't even grow on a rich agar plate. THey have their niche, and won't proliferate outside of it.

Surviving some harsh condition temoporarily doesn't mean they can survive in the long term and grow.

Its like worrying that a seed from a tree, which can go without water for a long time, will land in the sahara, and then convert the sahara into a forest.

That is astronomically unlikely :D

Such an organism would have to be able to survive on the alien habitat, through the space journey and thrive on earth in all of our different environments and be evolved in just such a way to be fatal to all of our different forms of life and be able to overcome the human immune system, antibiotics, and any adaptation that we could make as it spread.

Basically, if the variety of earth-bound viruses and germs can't kill us all, then a few alien ones won't either.

FWIW, if the life is independent of our own, our antibiotics are unlikely to have any effect.

It could come back as soil loosened and collected on our return craft, the nematodes after survived the last space shuttle disaster, including the reentry part. Bacterial spores might have an easier global re-entry.

So did video recorders, the crew was still making transmission 5 minutes after peak heating.

Anyway, I doubt Earth life could survive there:

First, the images of what might have been water on the struts of the Phoenix lander:

http://www.space.com/6394-phoenix-mars-lander-liquid-water-scientists.html

http://blogs.scientificamerican.com/media/inline/blog/Image/MarsWater_1000.jpg

Second, a paper from the Phoenix lander where liquid brines were inferred:

http://repository.brynmawr.edu/cgi/viewcontent.cgi?article=1011&context=geo_pubs

I'm assuming the water brine at the phoenic lander site was/is similar to the water brine at the RSL

A related paper, also based on the Phoenix data:

http://onlinelibrary.wiley.com/doi/10.1029/2012GL051239/pdf

(I hope you can see that, and it's not behind a paywall)... takes the measured composition of the soil by the Phoenix lander, and tests/models the solubility and water activity. The perchlotes were pretty much the last thing to start precipitating out of solution. The water activity got below 0.2

Then we have this paper about water activity limits for life on Earth.

http://www.nature.com/ismej/journal/v9/n6/full/ismej2014219a.html

The first sentence of the introduction is particularly relevant:

"Water availability (water activity (aw)) determines both the vitality and functionality of living systems. The majority of microbes cannot multiply below 0.900 aw (Brown, 1976; Manzoni et al., 2012; Moyano et al., 2013) and for the most extremophilic species, cell division has only been observed down to ~0.61 aw"

Also, in this regard, single celled prokaryotes are not the winners, but fungi are.

"The established water-activity window for cell division of archaeal and bacterial life (1–0.755; see Anderson, 1954; Grant, 2004) is narrower than that of some xerophilic fungi that are even able to grow and/or germinate in the range 0.755–0.605 aw (Pitt, 1975; Williams and Hallsworth, 2009). Hence the maxim that eukaryotic systems have evolved levels of solute tolerance superior to those of prokaryotes"

So it is important to note that many areas of the Atacama desert have been found to be sterile - nothing is growing. Some organisms will grow through deliquesence of hydrated salts in the atacama desert (the same mechanism by which they say this mars brine-water is likely forming) - but those hydrated salts at a water activity of even 0.5 do not support any life.

There is selection on this planet for organisms that can tolerate even lower salt activity, and there has been a lot more time than on Mars.

Nothing on this planet has surmounted the challenge of living in areas with a water activity of 0.5 or below

Martian perchlorate brines can form with water activities below 0.2...

That is 1/3 the lowest water activity needed for any known Earth life to proliferate.

I think, given the sterilization proceedures already done on the rover, and its long time in the UV and near vacuum environment of mars, that its not coming from a place that would even harbor extremophile organisms on Earth, and that no known life on Earth (extremophiles included) can survive at water activity levels anywhere near that low - that there is no significant risk of a rover contaminating these suspected brines.

Also... I'm pretty sure there are no martian microbes growing in those brines either.

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As inconvenient as they may be, it kind of makes me feel good that we have procedures in place to protect alien life. :)

Still, I hope we find a good way to study those regions without infecting the area.

A bit off-topic, but that's among the more likely reasons we haven't encountered extraterrestrials. If we're this careful now, then in the future if we discover Pandora or something, we're liable to take every possible measure not to even be noticed. So likewise, the extraterrestrials might be treating us the same.

Not that I'm saying anything for certain, just possibilities ;)

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As I have mentioned, any water-based life on Mars is very likely to have a common origin with that of Earth. This nullifies the "common" argument for life. It's been estimated that two percent of fragments from Earth impacts end up on Mars, and some bacteria can survive in space for a while.

When is the last time that would've happened though? I think after a few billion generations of microbes, it's safe enough to classify them as being Martian. Unless Mars has a really big problem with Amnesty.

A bit off-topic, but that's among the more likely reasons we haven't encountered extraterrestrials. If we're this careful now, then in the future if we discover Pandora or something, we're liable to take every possible measure not to even be noticed. So likewise, the extraterrestrials might be treating us the same. Not that I'm saying anything for certain, just possibilities ;)

I'm not one to assume alien abduction is real. If it is, there's probably only ONE case that someone reported that was genuine, and everybody else just leeched from it like a game of telephone until the original concept was completely lost. However, I do find it strange when people talk about it like, "Why would aliens EVER do anything like that?" All I can think about is how wild animals get tested. Someone tranqs them, sticks a tag on their ear, does a bunch of tests, and then leaves them somewhere to wake up with a migraine. From the animal's perspective, that sure sounds like the same darned thing.

But, yeah. On a subtler note, I think we can all agree that if knowledge of an advanced civilization were to come out tomorrow, we'd have total chaos on this planet. We know it, so the E.T.'s surely know it, and they're doing the responsible thing by NOT landing on the Whitehouse lawn.

Edited by vger
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But, yeah. On a subtler note, I think we can all agree that if knowledge of an advanced civilization were to come out tomorrow, we'd have total chaos on this planet.

Nope, we can't agree on that. (ie, I disagree)

There would be some disruptions, but not total chaos (assuming there was nothing to indicate hostile intent)

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Advanced alien life would be completely beyond our comprehension. It would be seen as a threat by one our 150 governments and attacked on sight.

There's really no reason for them to contact us at all.

Mutually assured destruction is hinged on the premise that the golden rule only applies in a situation of known mutual risk.

An example of this is negotiation with a suicide bomber, only another suicide bomber can negotiate on equal terms with him, and so they must treat each other in a civilized manner.

But the flipside of that is that absent known mutual risk, the inverse of the golden rule applies.

To do unto others as they most probably will do unto you, and to do it first.

Which is probably why we have not been contacted by any alien species, and also why broadcasting contact attempts is a really bad idea.

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Interesting concept, once you really start thinking about it.. Clearly, the norm in human history has been to exploit and demolish whatever natural habitats we encounter. This occurs even when the intrusion is done with the best of intent (which is rare).

Suppose we go to great lengths to avoid contamination, and then find alien bacteria on Mars. This implies that alien bacteria is very, very common in the universe. Do we now disregard it and terraform the planet? If we do not find alien life, how long do we wait to be sure, before terraforming?

Is it unethical to ever terraform, because the possibility exists of life developing there on its own at some point in the future?

There is no end to the questions that we should be debating and answering right now. Unfortunately, I see no such debate happening anytime soon (ever) in the public sphere..

Can bacteria or some (at best) small multicellular organisms experience pain, sadness, or loss? Does not eliminating them get in the way of continued human development and research?

No to the first and yes to the second, some bacteria is a small sacrifice to continued development and expansion, two things that must go on. Regardless of how common these bacteria are, if intelligent life does not exist there at that point; and because you are not harming said intelligent life if it does not, you know, exist; sterilizing the planet through terraforming and strip mining is perfectly acceptable in my opinion.

Though might I add, terraforming is completely impractical due to the required amount of energy, it would be much easier and more efficient to live underground than to terraform the surface.

Edited by NuclearNut
clarity, spelling errors
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Acceptable? It'd be unacceptable not to.

We've got a planet to mine, ore to smelt, metal to forge and work, and ships to build.

your funny, dude. Like what has Mars got that is worth the dV?

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your funny, dude. Like what has Mars got that is worth the dV?

Not much, if we ever expand off earth then it would be worthwhile for mars orbit, but you are right, transporting resources back too earth, at least at the current and near future launch and operation costs (excluding maybe orion) it would be too expensive.

Honestly the only reason I feel that human spaceflight could be practical in would be to conduct research that would not be exactly legal or safe on earth. For example, testing nuclear explosive devices, biological things that you really do not want to be a problem on earth, and anything else you could think of that would fit the category of too dangerous to do on earth. Other planets would make one hell of a dumping ground for dangerous stuff.

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Well, there's the fact that we're already in the middle of a mass extinction here. Maybe expanding to Mars would give some portion of humanity a chance...

Human is the only thing not in the supposed mass extinction. They've got seven or eight billion individuals, a number that is an order of magnitude above their population a century and a half ago. IMO they should only go to Mars in order to stop messing with Earth.

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No to the first and yes to the second, some bacteria is a small sacrifice to continued development and expansion, two things that must go on. Regardless of how common these bacteria are, if intelligent life does not exist there at that point; and because you are not harming said intelligent life if it does not, you know, exist; sterilizing the planet through terraforming and strip mining is perfectly

Sorry, but no. The possibility of life on other planets needs to be approached with a pretty open mind. We can use the very narrow view of what all life on this planet is like, and use that as a basis to look for it elsewhere. But we need to be REALLY careful while we're exploring. There's no reason to assume that all living things have DNA. Doesn't mean they don't have something similar, but it might not be something we would immediately recognize. We have no clue how diverse life might be. It'd be nice if we made sure before we steamroll and destroy all evidence of it.

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Sorry, but no. The possibility of life on other planets needs to be approached with a pretty open mind. We can use the very narrow view of what all life on this planet is like, and use that as a basis to look for it elsewhere. But we need to be REALLY careful while we're exploring. There's no reason to assume that all living things have DNA. Doesn't mean they don't have something similar, but it might not be something we would immediately recognize. We have no clue how diverse life might be. It'd be nice if we made sure before we steamroll and destroy all evidence of it.

And that's how the concept of Humanity as a multiplanetary species dies before it ever had a chance to live

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