Alien microorganisms - need reference material for mod

[kiwiak]

I plan to make mod about searching for alien microorganisms, but i need some reference material.

Are there any theories about life being able to live on surface of airless worlds like mun (actually live, not just hibernate like bacteria found on recovered moon probe). Or maybe some organisms living inside rocks, under surface?

How about life with different chemistry, like silicon based?

With more kerbin like planets i woudl stick to old fashioned cabon based life, but i woudl like to put few "types" of microorganism there, that player woudl be able to detect and sdiscern. What woudl be some simple pattern to discern them? (like anaerobes and aerobic bacteria).

[CaptainKipard]

Tardigrades can life without an atmosphere for a very long time.

[kiwiak]

Tardigrades can life without an atmosphere for a very long time.

They just hibernate and thats not what i was looking for.

[shynung]

Life that needs liquid Nitrogen instead of water to live?

If there are any, they'd survive in very cold, far away planets like Eeloo.

EDIT: I think this is a good start for a rough guide.

Edited March 26, 2014 by shynung

[kiwiak]

Life that needs liquid Nitrogen instead of water to live?

If there are any, they'd survive in very cold, far away planets like Eelo.

Than wee need to assume there is some ocean under surface, right?

[shynung]

Than wee need to assume there is some ocean under surface, right?

Liquid Nitrogen ocean, yes. Under the surface, not necessarily.

What if, in such a planet where there are landmasses and ocean, the 'land' are just frozen water?

[kiwiak]

Liquid Nitrogen ocean, yes. Under the surface, not necessarily.

What if, in such a planet where there are landmasses and ocean, the 'land' are just frozen water?

Thats how it works on titan.

[Doozler]

As a general rule, for normal-ish life* I thin you need

1) Some kind of liquid (water, Ammonia etc)

2) An energy source (sunlight, themal vents etc)

*normalish= not intelligent clouds of gas etc.

[shynung]

Thats how it works on titan.

Nah. Titan has a liquid water ocean underneath a frozen water-ice layer. The nitrogen there is mostly in the atmosphere.

Liquid nitrogen boils at 77.3K (-195.7°C). Planets having a liquid nitrogen ocean has to be far away from any star.

Other possibilities of ocean composition include ammonia, methane (or other hydrocarbons), and hydrogen fluoride.

This article on Wikipedia is a good reference, IMO.

Edited March 26, 2014 by shynung
Grammar correction

[Awaras]

If you haven't already, check out the "Building Blocks" part of this page (and the entire site while you are at it):

http://www.projectrho.com/public_html/rocket/aliens.php

[Sirrobert]

As far as we know, life needs some liquid to form in.

It's probably safe to say that a body that has always been barren will not have life. Bodys that used to have an atmosphere that's now gone (like mars) could still have some life left though

[KerikBalm]

I think he meant that the "land" on titan is mostly water ice

ie, in response to: "the 'land' are just frozen water?"

Titan has ethane/methane/'hydrocarbon' lakes, and a lare part of its "land" is frozen water ice

[shynung]

I think he meant that the "land" on titan is mostly water ice

ie, in response to: "the 'land' are just frozen water?"

Titan has ethane/methane/'hydrocarbon' lakes, and a lare part of its "land" is frozen water ice

That's what I meant. The 'land' of Titan is water-ice, frozen H₂O.

Kilometers underneath that ice layer, is a hidden ocean of liquid water. If there is life on Titan, it could be there.

[Scotius]

http://phys.org/news/2014-01-lichen-mars.html

Here's a link to article about terrestial lichen surviving, and even thriving in simulated Mars environment.

[Accelerando]

on a more specific level, you can use electrical detectors to find bacteria that communicate, transport materials with electricity for one.

bacteria living deep in the crust of a planet are likely to perform respiration by reacting metals in the absence of oxygen. this article's table on anaerobic respiration might be helpful.

[vger]

This is a great idea, and one of the things I've wanted added to the stock game. Not "alien civilizations" or insane creatures scurrying around, but simply the chance of finding something basic, even if it was only fossilized.

A suggestion (though I feel a lot of people may disagree with me) Don't put a huge limiter on the definition of "life." Many scientists can't even agree on whether or not virii classify as living organisms. And we've discovered other organisms in recent years that can survive without one or more of the commonly-accepted 'prerequisites' for sustaining life.

[magnemoe]

Well Laythe obviously has life, no other way to get an oxygen atmosphere, microbes and even some primitive swamps and corrals, something keep the ocean liquid.

Duna is Mars, good chance for life.

Eve would be next candidate as it has oceans, not water but something who stays liquid around 100 degree, Not sure what, Not water based as on Laythe and Duna

Both Val and Minmus is not rock, probably water / hydrocarbon. Good chance for life, in Minmus the hydrocarbons protect the water below, this was discovered by the first miners drilling for stuff who could be made into fuel off planet.

Jool might have layers with decent chance of life, more so as its and good chance impacts on Laythe dumped rocks into Jool.

[KerikBalm]

"And we've discovered other organisms in recent years that can survive without one or more of the commonly-accepted 'prerequisites' for sustaining life. "

Such as? I sincerely hope you are not referring to that terrible and soundly refuted "arsenic life" paper.

Whether or not viruses are life is a matter of definition or semantics. It is clear that they are biological entities - no biologist will dispute that.

If we just rephrase the question to alien biological entities, then we bypass this issue as well.

"Well Laythe obviously has life, no other way to get an oxygen atmosphere, microbes and even some primitive swamps and corrals, something keep the ocean liquid."

Not strictly true, but very suggestive of life.

Duna != Mars, but it we assume that is true, it may still be lifeless. Duna is in many ways better than mars now (maybe not mars in the past), given that its atmospheric pressure is ~20x greater than that of Mars. Actually, given its atmospheric pressure, and temperatures, it certainly *should* have liquid water.

Maybe the Devs just didn't want to make landing there too hard. Imagine landing on Duna, with 1/20th its atmosphere (even landing at the highest points would be easy) - oh, and increase its gravity by 25%

Also, those mars lichen experiments still don't show that it can survive long term. It survives ~30 days, and unlike tardigrades, does show some metabolic activity in those 30 days, but they are likely still dying, and certainly not reproducing, given the lack of water.

Eve- actually, at those atmopheric pressures, it *could* be water - but if it were, Eve should be a lot hotter, and then the water wouldn't last very long (lost to space, as with venus - maybe Eve is like an early venus?)

Minmus- doesn't make sense for it to be ice, given that its at the same distance from the sun as kerbin, the day side near the equator would sublime off into space... and it should have a big coma like a comet

Edited March 26, 2014 by KerikBalm

[Sidneyia]

It seems, right now, that life is bound to liquid state. Besides Kerbin, Laythe and Eve, there is no other body with liquids on the surface (correct me if I am wrong). So, if there is life in other planets, should be in underground oceans. How thick could be the layer of rock/ice to be drilled with a device? I don’t know.

However, I think that a planet that could have liquid state medium at least during the day, could feed bacteria from polyhydrocarbon molecules found on the surface. These molecules could come from a lost early-generated atmosphere at the beginning of the solid state of the planet. If it is not possible (I don’t know), they could come from impacts of asteroids and meteors. The polyhydrocarbon (or polyhydrosilicon xD) could serve as a source of C (or Si) and energy (all what bacteria need). Bacteria can also get energy by oxidation or reduction of Fe, S, and many others, elements that could be present in the surface. (Other bacteria could undo the process of the oxidation/reduction made by the others to get energy as well, and thus, establish a recycling cycle).

In any case, everything would freeze during the night and the bacteria would start hibernation until the next day. I know we are talking about the vacuum, and we don’t know yet anything that can grow in these conditions. “Let’s imagine†these bacteria are adapted to these conditions. Maybe the daylight could create a micro atmosphere due to the volatilization of some compounds. This could be a little better for hosting life.

These are my bases. Then, I think we should not go into detail concerning what is going to happen with the DNA/RNA, proteins, lipids, sugars… cause we will need N, P, S, trace elements,… and we will get lost. I think anything could be possible; after all, arsenic based DNA exists.

[Kryten]

I think anything could be possible; after all, arsenic based DNA exists.

No it doesn't.

TL;DR: the original researchers could only test the cell fraction (from centrifugation) that included DNA, RNA, and a few other things. Direct analysis of purified DNA shows no arsenic.

[KerikBalm]

http://scienceblogs.com/pharyngula/2011/05/30/further-panning-of-the-arsenic/

http://www.nature.com/news/2011/110527/full/news.2011.333.html

I am so so so so soooooo tired of hearing this claim repeated by laypeople. The publishers were criminally negligent IMO.

There is no good evidence that the bacteria incorporated arsenic into its DNA, and ample evidence that it did not.

All they did was find a bacteria that can tolerate higher levels of arsenic without dying.

They grew bacteria in high arsenic conditions with low-but-still-there levels of phosphorus.

They then detected arsenic in their bacteria, and concluded arsenic had replaced phosphorus. - A huge unsupported logical leap

Sure, they claim to have purified the DNA, but they did it so half-assed, omitting very cruicial steps, that there would still be many contaminants. IIRC, they didn't even have a proper negative control.

Stop repeating these asinine claims, and if you're in a conversation with someone else who repeats the claim, correct them.

Stop the spread of a poorly informed public.

The ironic thing is that these people repeating this arsenic life claim actually think they are well informed.

“He who knows not and knows not he knows not: he is a fool - shun him. He who knows not and knows he knows not: he is innocent - teach him. He who knows and knows not he knows: he is asleep - wake him. He who knows and knows he knows: he is wise - follow him.â€Â

I'd modify that saying to not go straight to shunning people, but first try to expose their ignorance, and then see how they react.

Edited March 28, 2014 by KerikBalm

[vger]

"And we've discovered other organisms in recent years that can survive without one or more of the commonly-accepted 'prerequisites' for sustaining life. "

Such as? I sincerely hope you are not referring to that terrible and soundly refuted "arsenic life" paper.

Well, our understanding of how life originally got started is pretty limited, given just how long ago we think it started. It seems silly to me to assume that we came from the ONLY possible recipe for 'primordial soup.'

But no, I wasn't thinking of that. Just extremophiles in general. I wanted to go back and find some of the better examples I've read about over the years, but there's SO much out there that finding the examples I wanted would take a long time. Here, just read Cracked's list and maybe have a laugh at the same time. http://www.cracked.com/blog/the-7-most-mind-blowing-places-science-has-discovered-life/

[Kryten]

Extremophiles change nothing. They simply live in more extreme environments, there aren't any that lack e.g. need for phosphorus or a terminal electron acceptor.

[KerikBalm]

Well, our understanding of how life originally got started is pretty limited, given just how long ago we think it started. It seems silly to me to assume that we came from the ONLY possible recipe for 'primordial soup.'

But no, I wasn't thinking of that. Just extremophiles in general. I wanted to go back and find some of the better examples I've read about over the years, but there's SO much out there that finding the examples I wanted would take a long time. Here, just read Cracked's list and maybe have a laugh at the same time. http://www.cracked.com/blog/the-7-most-mind-blowing-places-science-has-discovered-life/

Actually, our understanding of how life got started is much better than it was even 10 years ago. The RNA world hypothesis has come together nicely with recent findings of RNA ribozymes, which have been getting (or rather, the forms we have evolved recently) more and more advanced. We now have RNA ribozymes that can copy other RNA sequences longer than themselves.

As to your link, all of those cannot "survive without one or more of the commonly-accepted 'prerequisites' for sustaining life."

They all require H20, and C, H, O, N, and P.

I challenge you to point out something that they can survive without, that you would consider a "commonly-accepted pre-requisite for sustaining life"

For anything you point out, I gaurantee I can find papers showing it was well known to the scientific community that it was not a pre-requisite.

Also:

http://scienceblogs.com/webeasties/2010/12/05/guest-post-arsenate-based-dna/

[vger]

I'm not just talking about chemicals, but general environmental factors as well. Temperature, light, pressure, moisture, etc. Even though some think that, for example, Europa, may be capable of sustaining life, the classic "sweet spot" of a planet's distance from its mother star (factoring in how hot the star is) is still generally considered a necessity in the search for possible E.T. worlds in other star systems.

I'm not arguing the chemical composition of life on Earth because anything on Earth would have evolved from the same source. If 'arsenic life' or something similar would ever turn up on Earth, it would probably be something that arrived here from someplace else. Even bringing up RNA when discussing the possibility of life on other worlds though, drastically limits the search parameters. For life "as we know it" it makes sense, but we have no rule book to say that ours is the only possible starting point in all the universe.

Edited March 28, 2014 by vger