Mars-Like Conditions Sufficient to Sustain Earth-Bound Microbes

skade88 writes "Does life exist on Mars? We might assume if there ever was life on Mars then it most likely came about when Mars was a wetter and warmer place than it is now. So the question is, if life did exist on Mars in the past, does it still exist? Ars takes a look at how microbes have survived on Earth in environmental conditions much like we currently see on Mars."

Comments

They're Earth-bound?

[plate_o_shrimp]

When are they expect to arrive here?

Re:They're Earth-bound?

[Dunega]

Wouldn't they be little green zombie mutants?

Re:They're Earth-bound?

[mcgrew]

Well, woosh me bald...

Earth-bound as in "microbes that are on Earth and can't leave". In short, microbes from earth could live on Mars. Not bound FOR earth, bound TO earth.

Hope you get that +5 funny you're going for, but I didn't think the joke was that good.

Good and bad

[Hentes]

On one hand, we have to be even more careful not to contaminate Mars. On the other hand, finding (or creating) bacteria that can survive there could be the first step of terraforming the planet.

Re:Good and bad

[Baron von Daren]

One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere. Earth’s magnetosphere greatly mitigates solar wind and radiation. Solar wind can strip a planet of its atmosphere and solar radiation isn’t good news for ‘earth like’ life.

The conditions for life might be quite common in the universe, but the conditions for complex Earth like life are much, much more rare (but perhaps still substantial given the numbers). We have a lot going for us here. We are part of a solar system in a ‘quiet’ part of the galaxy. The vast majority of stars in our galaxy, and most others, are in areas of great cosmic violence. They are too close to the galactic core, or too close to a star that goes supernova or hypernova during the evolutionary process. There are planets that don’t have a moon or nearby supergiant plants (like Jupiter, Saturn, etc.) to protect them from comets and asteroids, and they don’t have strong magnetospheres. Of course a planet like Mars does have a lot of these things going for it, it doesn’t have a strong magnetosphere which is a sizable technological hurtle to terraforming (assuming we are terraforming for us).

Most likely humans will become largely virtual data based organisms long before we develop the technology or focused the resources on things like terraforming planets. If this happens, the need to do things like terraforming other planets kind of goes away.

Re:Good and bad

[N0Man74]

Why do we have to be careful of contaminating a barren wasteland that only the most ignorant could possibly believe ever contained life.

Exactly! It's kind of like the Sahara or Antarctica. One look is enough to know that plant life could not flourish in these areas. Only an ignorant person could think that these places could have ever supported abundant flora, because it's not possible that time could have changed the environment.

Re:Good and bad

[skade88]

Exactly! Looking a the Sahara today and saying it was always like that in the past would be at best an error. At one point, what we now call the Sahara Desert was covered with abundant life, both plant and animal. Continental drift and climate change has ensured that the surface of Earth is always changing. The same applies to Mars, saying that the surface of Mars has always been as it is today is very not correct.

Re:Good and bad

[Fluffeh]

One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere.

It's okay, I have seen the movie, all we need to do is to get these drill like vehicles, form them up into a train like system, pop a bunch of nukes on board, drill carefully into the core avoiding the city size diamonds, then set of a chain reaction that will resonate through the inside of the planet causing the molten iron to start rotating again and BAM! magnetosphere! Seriously guys, it's not that hard!

*sips coffee*

Re:Good and bad

[flayzernax]

Not to mention, that for a long time, there was abundant life on earth, and no, um plants, or animals.

There is plenty doubt as to whether or not there's life on mars, theres a good chance. And if someone knows about it, its not us. Though many great scholarly people conclude that life is far more pervasive then we are taught in highschool biology.

Deep in the mantle, and in space dust itself.

Re:Good and bad

[khallow]

One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere.

If you're trying to make a nice environment for people to go from Earth, it's a problem. If you're merely trying to get life to thrive on Mars, then it's not a serious issue.The moderately high radioactive environment of Mars just isn't that big an issue (especially compared to the UV enivornment!). The low gravity of Mars does more to strip Mars of atmosphere than the lack of a magnetosphere.

Most likely humans will become largely virtual data based organisms long before we develop the technology or focused the resources on things like terraforming planets.

We already terraformed Earth. Agriculture and urbanization both make huge swathes of Earth more habitable for humans (which really should be the definition of terraforming not making something more like arbitrary Earth environments which in themselves need not be particularly nice environments. Nor is there a reason to expect that that the process can't be largely automated (to avoid the need for billions of human laborers making things happen).

No, the question is: what happened

[Rob Kaper]

The real question is: if Mars once had Earth-like conditions, is there a risk Earth will end up with Mars-like conditions in the foreseeable future?

Re:No, the question is: what happened

[flyingfsck]

Yes, eventually the earth will cool down and the seas will sink into the crust and the surface will be dry just like the moon, Mars, Pluto, Mercury and other cold planetoids.

Re:No, the question is: what happened

[Anonymous Coward]

I don't think anyone is suggesting that because these microbes can suvive in Mars-analogue conditions that Mars is or was "Earth like". Like the authors and some other commenters have pointed out, these experiments covered low temperature, low pressure and low oxygen/high carbon dioxide, but didn't account for things like solar radiation or the chemical makeup of the soil. I'm not saying they're crap, but everyone agrees that they're partial and preliminary.

Besides, from what little I know of planet formation, Mars lost its atmosphere because its core cooled faster and when the magnetosphere was lost so was the atmosphere, which led to the cold and barren surface forming. I guess the same will theoretically happen to the earth one day but I'd guess that's on a similar timescale to "eath gets devoured by an expanding sun".

Re:No, the question is: what happened

[Thiez]

Nope, we're going to burn instead: http://en.wikipedia.org/wiki/Sun#Earth.27s_fate

Re:No, the question is: what happened

[mrsquid0]

Earth is much more likely to end up something like Venus than Mars. The Sun is slowly getting hotter, and by about 750 million years from now (give or take a few hundred million years) the temperature on the surface of the Earth will be hot enough that the oceans will be lost into space, and subducted into the Earth's mantle. With no oceans plate tectonics will grind to a halt, which will stop the recycling of carbon dioxide. The combination of large amounts of water vapour and CO2 in the atmosphere will lead to a runaway greenhouse that will cause temperatures on the Earth's surface to reach perhaps several hundred degrees. Mars, however, could end up warm enough to be habitable for a while.

Re:No, the question is: what happened

[Smidge204]

The sun isn't getting hotter. Water vapor isn't light enough to escape Earth's gravity well in any appreciable quantity. Plate tectonics are driven by convection currents in the Earth's mantel, not the oceans, and if anything the (extremely unlikely) ceasing of tectonic activity would decrease CO2 emissions.
=Smidge=

Re:No, the question is: what happened

[mrsquid0]

Yes, the Sun is getting hotter as it evolves across the main sequence of the Hertzsprung-Russell diagram. However, this is happening on a time scale of hundreds of millions of years. You are right that it has absolutely no effect on our climate today, but it will over the next 200 million years or so. Water vapour does not escape into space, but it will become a larger part of the atmosphere as the Earth heats up, and water vapour is a very potent greenhouse gas. Eventually the water vapour will be lost. First, as the atmosphere heats up the random motion of water vapour molecules will increase, so more of them will end up in the high-velocity tail of the Maxwell-Boltzmann distribution, and thus have enough speed to escape. Second the changes in the chemistry of the atmosphere will make it easier for water molecules to chemically dissociate (and cosmic rays will contribute too). The net effect is that water vapour will be lost, but on time scales of hundreds of millions of years. Plate tectonics are driven by convection currents in the mantle, but they are lubricated by water. If there are no oceans it is much harder for plates to subduct. Once the oceans are gone plate tectonics become much more difficult. This is thought to be the reason that Venus, a planet with essentially the same mass and internal composition as the Earth) shows no evidence for having plate tectonics. My understanding is that this is still somewhat hypothetical, but that there is an emerging consensus in the the geological community that oceans play a major rôle. Finally, plate tectonics do not drive geological CO2 emission, vulcanism does. While it is true that plate tectonics does cause vulcanism volcanos can happen without it, as we see on Venus, and in Hawaii. So, when plate tectonics stop there will still be CO2 emission from vulcanism. However, the carbonate-sillicate weathering cycle will have stopped, and this is the primary geological way of removing CO2 from the atmosphere. The net effect will be CO2 being added by volcanos, but with nothing to remove it the concentration of CO2 in the atmosphere will increase. Unless if we buy some Puppeteer world-moving technology Earth is in for a hot time around its 5,500,000,000th birthday.

Re:No, the question is: what happened

[Thiez]

Your "The sun isn't getting hotter"-article is looking at decades, not millions of years. What the sun has been doing since the 1980s is quite irrelevant to its evolution on larger time-scales. Even your water-vapor article concludes that the oceans could be boiled away if the earth were hotter, in the second to last paragraph.

Do you even read your own references?

Re:No, the question is: what happened

[skade88]

Mercury is a cold planet?!

Re:No, the question is: what happened

[Fluffeh]

Mercury is a cold planet?!

It sort of is actually, at least on the shady side.

Mercury's surface experiences the steepest temperature gradient of all the planets, ranging from a very cold 100 K at night to a very hot 700 K during the day.

Surface temp.
Min : Poles 100 K - Equator 80 K
mean : Poles 340 K - Equator 200 K
max : Poles 700 K - Equator 380 K

Forget accidental contamination.

[runeghost]

How long before some nation or well-funded group decides that the time to start terraforming Mars is 'right now', and without bothering about world opinion, puts together a tailored package of microbes at just lobs them to Mars?

Re:Forget accidental contamination.

[NEDHead]

I smell a Kickstarter campaign!

Re: Blattaria Planet

[retroworks]

More specifically, let's start a Kickstarter campaign to put cockroaches on Mars. Lots of them, enough for them to eat each other and evolve quickly into a apecies that human religions, races and nations can rally against in a uniform cause. I think we could convince enough people it's a really really good idea.

Re: Blattaria Planet

[ColdWetDog]

Isn't there a limit on Kickstarter funding? Some of those politicians are pretty husky - it's going to take a bit of cash to get them to Mars.

But I heartily support your idea and would like to subscribe to your newsletter.

Re:we should start terraforming Mars immediately

[Immerman]

If we sent some Earth-based microbes that need help incubating on Mars, then definitely. On the other hand if we specifically designed a fast-multiplying terraforming cocktail that could thrive in Martian conditions (probably well beyond our abilities for at least the next few decades) then the transformation could be almost overnight thanks to exponential growth. A single bacteria given unlimited food and a danger-free environment could grow to a colony out-massing the Earth in under a week. Sounds implausible I know, but at 1 division per hour you get 2^(24*7) = 4*10^50 individuals in a week. Multiply by an average bacteria mass of ~1x10^-12g and you get 4x10^35kg, over 60 billion times the mass of Earth.

And once you cover Mars with a living skin pumping oxygen and water into the atmosphere the transformation could be quite rapid.

Re:we should start terraforming Mars immediately

[Dcnjoe60]

If we sent some Earth-based microbes that need help incubating on Mars, then definitely. On the other hand if we specifically designed a fast-multiplying terraforming cocktail that could thrive in Martian conditions (probably well beyond our abilities for at least the next few decades) then the transformation could be almost overnight thanks to exponential growth. A single bacteria given unlimited food and a danger-free environment could grow to a colony out-massing the Earth in under a week. Sounds implausible I know, but at 1 division per hour you get 2^(24*7) = 4*10^50 individuals in a week. Multiply by an average bacteria mass of ~1x10^-12g and you get 4x10^35kg, over 60 billion times the mass of Earth.

And once you cover Mars with a living skin pumping oxygen and water into the atmosphere the transformation could be quite rapid.

Okay, I'll bite. Question 1 - Why would we do such a thing in the first place? Question 2 - exactly where is this man made bacteria going to get the nutrients on Mars, particulalry in quantity enough that it would be able to pump out oxygen and water? Or are we going to have to transport the oxygen and hydrogen to Mars to make that work and if so, why don't we just pump out the water (of course it doesn't solve the question of where are we going to get enough oxygen and hydrogen to supply an entire second planet without depleting this one).

Science fiction is nice, but unless you are talking about engineering a bacteria that can somehow transform atoms of one element, say silicon, into atoms of another, you don't have the raw materials on Mars, at least in sufficient quantity to produce the effect you are wanting.

Re:Procariotes

[flyingfsck]

When the aerobic life on the surface of Mars died, the underground life would have been unaffected. So if there was life on Mars, the place to look today, would be underground, since anaerobic life should still be there.

Re:At some point

[Jeng]

The next big step for mankind will be getting off this rock.

What will motivate us to get off this rock is a lack of terrestrial resources.

So once society gets to the point that it isn't economical to just rape our own planet then we will leave it, but not before that point.

Re:we should start terraforming Mars immediately

[Immerman]

1) Terraforming of course. You want to try to do it by hand? Seems a waste to leave a perfectly good planet lying around as a frozen desert if we can figure out how to cheaply make it more Earth-like.

2) Make 'em chemovores - lots of microbes on Earth survive primarily on inorganic compounds, no complex organics or light needed. As for raw materials - there's LOTS of oxygen on Mars, it's just bound up as iron oxide - hence the "red planet". We could also get it from the carbon dioxide which makes up over 95% of the Martian atmosphere, but since CO2 is a greenhouse gas and warming the planet will be one of the major challenges that might be counter-productive. Hydrogen might be a little less convenient, but it is the most common element in the universe, and the presence of methane (CH4) plumes in the atmosphere is clear evidence that it's present on Mars.

Considering how potent a greenhouse gas methane is I would suspect that one potential terraforming route would be to boost atmospheric methane until the temperature rose to the point where water vapor could exist is large quantities, then release new microbes that would create free water which would then help stabilize the system (assuming methane is as short-lived on mars as it is here, offhand I can't remember why it has such a short atmospheric life)

So no SF elemental transmutation is necessary - the building blocks of life, C,H,O,N, are among the most common elements in the universe - it's unlikely they'd be in short supply anywhere in a young star system, and certainly not in ours.