[HN Gopher] Dark microbiome in Atacama fossil delta unveils Mars...
___________________________________________________________________
Dark microbiome in Atacama fossil delta unveils Mars life detection
limits
Author : benbreen
Score : 59 points
Date : 2023-08-08 15:23 UTC (7 hours ago)
(HTM) web link (www.ncbi.nlm.nih.gov)
(TXT) w3m dump (www.ncbi.nlm.nih.gov)
| Aardwolf wrote:
| What would be wrong with the following:
|
| Launch a spacecraft to Mars full of organic material. Add the
| toughest possible bacteria (the kind that manages to survive in
| volcanoes for thousands of years), vegetable growing experiments,
| etc...
|
| Then see what sticks. Maybe it's nothing. But in the small chance
| something sticks, then humanity might have done the most useful
| thing ever, even in case humanity would go extinct: seed life on
| another planet.
|
| But instead we seem to be carefully disinfect any spacecraft
| launched to Mars from biological life instead...
|
| Is this for:
|
| A) to avoid contaminating possible life that would already be
| there?
|
| B) to ensure that if life is detected, we're sure it's not life
| from Earth that was present on the spacecraft itself?
|
| But, is the chance that life is already present there considered
| that high?
|
| How long can we keep maintaining that? At some point we've gotta
| either send something that's good enough to inconclusively tell
| whether there already is life there (when are we expected to have
| the tech to achieve that?), or send something with life.
| thanatos519 wrote:
| Apparently it's for both reasons, but I think both are
| bullshit. I love Star Trek, but the Prime Directive is not my
| flavour of Kool-Aid.
|
| In the case that life has only evolved here, it is our duty as
| the agents of DNA to spread it far and wide! We should be
| initiating panspermia to anywhere, starting with the places it
| is most likely to take hold. Send cultures of every
| extremeophile available and hope that sentience re-evolves
| after millions of years.
|
| I just found this and expect to agree with their manifesto:
| http://www.panspermia-society.com/
| giantrobot wrote:
| So you want to dump invasive species in protected
| environments. Great plan. Nothing could ever go wrong with
| that.
| dotnet00 wrote:
| Most of these contamination concerns are only relevant while
| we're still at the robotic exploration stage. When humans
| inevitably set foot on the planet in a couple of decades most
| contamination concerns become moot since it's basically
| impossible to contain the amount of life that comes along with
| any animal, especially when you have the systems to sustain
| those animals for years.
|
| It's a somewhat ironic situation I think, since with how
| limited our ability to explore is with robotic probes and how
| limited even the sample return's sampling area would be, the
| only serious shot at actually ruling out the potential for
| native Martian life would come with a years long human presence
| (as would be needed due to the 2 years between arrival and
| return windows) and the associated ability to more thoroughly
| explore - either in terms of actually having people going
| around and exploring or in terms of just being able to be more
| flexible in performing experiments on samples brought over by
| robots.
|
| In a way the sample gathering (and potential return) is also in
| preparation for this inevitability. NASA is well aware that if
| the plans working up to a boots on Mars materialize, having
| 'pristine' reference samples will be pretty important, so even
| if they can't bring them over to Earth yet, they can at least
| preserve them for later reference.
| pazimzadeh wrote:
| The reason is mainly B with a little A. I agree with you
| though. But maybe we should try it on the moon first.
| tiffanyg wrote:
| It's for reasons A and B, at least. There have already been
| issues with "B", for example:
| https://www.smithsonianmag.com/smart-news/crashed-spacecraft...
|
| Look at how "well" transferring species around has worked out
| on Earth, regardless of intentionality:
|
| https://wildlife.org/eradication-lets-rat-island-shed-its-na...
|
| https://www.nbcnews.com/news/forget-lantern-fly-mysterious-n...
|
| ... actually, here, let's just cover things more completely/
| efficiently:
|
| https://en.m.wikipedia.org/wiki/Lists_of_invasive_species
|
| It seems wise, for multiple reasons, to try not to cross-
| contaminate, for the moment. Just in light of unintended
| consequences with past "cross-contamination" events.
|
| Something like "Andromeda Strain" may be unlikely, and, it may
| be that we don't find anything particularly interesting on
| Mars, period, say... But, we're still very early on in this
| phase, I'd say ... trying to avoid some of the consequences
| created by past explorers (who spread diseases, rats, etc.
| everywhere - whether European or Pacific Islander or etc.)
| seems prudent...
| jl6 wrote:
| I imagine it's for both reasons A and B, and we will keep doing
| it for as long as we can presume Mars to be pristine. If we get
| to the point of having millions of human colonists roaming the
| landscape, it will probably no longer be worth sending highly
| clean spacecraft.
| Aardwolf wrote:
| There has to be some stage in-between millions of human
| colonists and the current state though.
|
| Also, why Mars specifically? Does this "must be pristine"
| policy also apply to other plants? Not to the moon at least,
| that's for sure.
| fooker wrote:
| It does apply to the moon.
|
| Everything we have sent to the moon has been carefully
| disinfected as far as we know.
| Aardwolf wrote:
| Even when people visited, opening and closing doors (even
| if indirectly through an airlock)?
| dotnet00 wrote:
| With the Moon there's at least the argument that any
| contamination likely couldn't travel too far due to the
| lack of wind. So any contamination there would just be
| around the landing site, only going as far as the
| depressurization might've allowed it to go. Plus since
| the Moon is exposed to completely unshielded solar
| radiation, any unsheltered contamination will probably
| have broken down.
|
| Mars on the other hand has wind, is slightly more
| protected by the atmosphere and increased distance from
| the Sun and around the equator summers are actually at
| decent temperatures for life.
| KineticLensman wrote:
| The Lunar Module didn't have an air lock. They just
| depressurised and opened the hatch.
| jl6 wrote:
| It's not just Mars, but there are nuances and exceptions.
| There's a ton of history on why we do this and what the
| limitations are:
|
| https://en.wikipedia.org/wiki/Planetary_protection
| samus wrote:
| Mars and some other places like Europa are suspected to
| host or to have hosted life at some point. It's worth
| applying this policy uniformly because spores are quite
| hardy and it can be surprising where fragments of
| contaminated celestial bodies might end up. Even thoroughly
| scrambled genetic material could influence the development
| of extraterrestrial microbes whose biochemistry might or
| might not be compatible with the genetic language of life
| on Earth.
| interroboink wrote:
| > most useful thing ever ... seed life on another planet
|
| I don't intend to change your mind on this point, but I'll just
| say I disagree (:
|
| Why not pave over national parks and build more cities? Seems "
| _useful_ "...
|
| This is very much a "Red Mars / Green Mars" sort of debate (see
| the books by Kim Stanley Robinson; not that I'm a huge fan, but
| it's very topical).
|
| You'll always have some people who want to forcibly mold the
| world/universe into something else, and some people who want to
| preserve what's there, and a whole spectrum in between.
|
| If nothing else, once you _do_ contaminate /bless Mars with
| life, there is no going back. So, it seems reasonable to take
| advantage of the unique opportunity to study it before crossing
| that line.
|
| Just my 2C/
| bcoates wrote:
| If my childhood experiments with anything amenable to a
| screwdriver are anything to learn from, you'll learn more
| from breaking it than looking at it. We can always use all
| those pointless atomic bombs we spent billions on to
| sterilize it from a safe distance if things get out of hand.
| Wojtkie wrote:
| I don't see how you can think nuking something just
| "resets" it. The whole point of sanitizing probes and not
| introducing foreign microbes to Mars is specifically so
| that we keep it separate from human intervention. Once you
| introduce a microbe, there's no coming back.
|
| Nuking it isn't a solution and "move fast and break things"
| is extremely irresponsible and ignorant when it comes to
| things like ecology and geography.
| tivert wrote:
| > Launch a spacecraft to Mars full of organic material. Add the
| toughest possible bacteria (the kind that manages to survive in
| volcanoes for thousands of years), vegetable growing
| experiments, etc...
|
| > Then see what sticks. Maybe it's nothing. But in the small
| chance something sticks, then humanity might have done the most
| useful thing ever, even in case humanity would go extinct: seed
| life on another planet.
|
| How would it be useful (in the sense I think you mean it to
| be)? Mars is pretty dead, and seems likely to stay that way
| forever (e.g. cold, dry). Any seeding, if successful, isn't
| going to result in some Star Trek-like scenario that results in
| intelligent life arising in a billion years. The only result
| will be bacteria eking out an existing in a marginal habitat
| for a billion years.
|
| > How long can we keep maintaining that? At some point we've
| gotta either send something that's good enough to
| inconclusively tell whether there already is life there (when
| are we expected to have the tech to achieve that?), or send
| something with life.
|
| The only upside I see to sending a spacecraft like you propose
| is to _irreversibly contaminate_ Mars with life to eliminate
| the scientific basis for avoiding colonization and exploitation
| of it.
| [deleted]
| arciini wrote:
| > Our analyses by testbed instruments that are on or will be sent
| to Mars unveil that although the mineralogy of Red Stone matches
| that detected by ground-based instruments on the red planet,
| similarly low levels of organics will be hard, if not impossible
| to detect in Martian rocks depending on the instrument and
| technique used. Our results stress the importance in returning
| samples to Earth for conclusively addressing whether life ever
| existed on Mars.
|
| This study seems to support the Mars Sample Return Mission, which
| has been controversial lately due to its high costs:
| https://arstechnica.com/space/2023/07/the-senate-just-lobbed...
|
| > The concern expressed by some scientists, including former NASA
| science chief Thomas Zurbuchen, is that the ballooning cost of
| Mars Sample Return will cannibalize funding from other science
| missions. And if the price is already approaching $10 billion
| now, then it is likely to spiral further out of control.
| irrational wrote:
| > Our results stress the importance in returning samples to Earth
| for conclusively addressing whether life ever existed on Mars.
|
| If nothing is found in the returned samples, how would that be
| conclusive?
| samus wrote:
| Those samples could indeed only prove that life existed.
| Proving the nonexistence of something is, as expected, much
| more difficult.
| 1970-01-01 wrote:
| _Life as we know it_
|
| It's possible to find something else entirely detached from what
| we call life, although this would be much more unlikely.
| bmau5 wrote:
| Interesting choice to use 16s sequencing for analysis vs. shotgun
| metagenomics. I guess they were intentionally looking for
| bacteria but shotgun would give a more unbiased and comprehensive
| view of any microbial (or other) species present
___________________________________________________________________
(page generated 2023-08-08 23:01 UTC)