Scientists Look at Martian Salt for Ancient Life

eldavojohn writes "Is there life on Mars? Maybe not, but a better question might be whether or not it has ever existed on Mars? Scientists are claiming that the best indication for this will be in newly found evaporated salt deposits on Mars which they can use to check for cellulose. Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth. Jack Griffith, a microbiologist from UNC, is quoted as saying, 'Cellulose was one of the earliest polymers organisms made during their evolution, so it pops out as the most likely thing you'd find on Mars, if you found anything at all. Looking for it in salt deposits is probably a very good way to go.'"

Comments

Salt and astrobiology

[Geoffrey.landis]

Salt on Mars has been a topic of interest for a while-- I wrote about the implications of Martian salt for Astrobiology a couple of years back, in an article in Astrobiology

Look for the Margarita glasses

[UberHoser]

D.E.L.I.C.I.O.U.S. !

slightly inaccurate summary

[cowscows]

The article summary says that the cellulose found in 250 million year old salt is the oldest known evidence for life on Earth. That's not true, there's ample of evidence of life for billions of years before that. The article states that the 250 million year old salt is the oldest biological substance known, which is pretty cool, but there are plenty of other types of evidence for life besides just finding dead tissue.

Re:slightly inaccurate summary

[Gat0r30y]

Radioactive decay is a pretty well understood phenomenon. The strong force (and weak too) in the nucleus of radioactive elements isn't quite strong enough to contain all the protons and neutrons in there, causing alpha and beta particles to come flying out from time to time (causing decay to another element in the case of a proton, and another isotope in the case of a neutron). By measuring the ratio of isotopes, we can figure out when a rock was formed. And, it all fits quite neatly in our standard model.
So you are left with a choice, believe that the standard model is pretty much right, and thus the Earth must be ~ 4.5 billion years old, or deny the standard model. However, if you choose to deny the standard model, I would most sincerely enjoy your recaboobeling of quantum mechanics to explain this discrepancy.

Re:slightly inaccurate summary

[Anonymous Coward]

He can't do that. He's too busy at church.

Re:slightly inaccurate summary

[Chris Burke]

Well, the way it works for organic tissue and radio-carbon dating is that new higher isotopes of carbon are being created all the time, and have a generally equal distribution in the environment at large. When an organism is alive, it will continuously take in new carbon from the environment (food, CO2 for plants, etc) and thus maintain the same ratio of carbon isotopes. When it dies, however, it stops taking in new carbon, and thus slowly the existing radioactive isotopes will decay and not be replaced so the ratio decreases and you can calculate the age.

I only use the example of radio-carbon because I'm familiar with it. I'd assume it's somewhat similar with dating geologic formations, in that while say sediments are being deposited on a river it's being exposed to a constant influx of new material, but once the sediment is well buried it becomes 'fixed'. But like I said, that's an assumption.

Re:slightly inaccurate summary

[MightyMartian]

Start here. It also includes all the necessary references for going to the primary literature if you think all those evil atheist scum in talkorigins.org are just making it up:

http://talkorigins.org/faqs/faq-age-of-earth.html

In fact, I suggest you probably spend some time at that site.

Return Sample?

[Gat0r30y]

Wouldn't this require a sample coming back here? It looks like they needed a Scanning Electron Microscope to see the cellulose fibers. It seems to me they would have to return a sample of the salts in order to see anything. Are there any plans for a sample return mission to mars anytime soon?

Re:Return Sample?

[Tablizer]

they needed a Scanning Electron Microscope....Are there any plans for a sample return mission to mars anytime soon?

I hope not. The possibility that it may contaminate Earth with a Mars infection we have no immunity for is too high. Even a 1-in-a-million chance is not worth it. Would you want to take a 1-to-million gamble with all of humanity? (Please, no G.W.Bush jokes). We'd probably need to set up an orbiting or moon base lab for that so that any infected workers are incubated away from Earth for at least a few years.

Re:Return Sample?

[Tablizer]

You've been watching too much sci-fi...It's unlikely that something from such a wildly different evolutionary line would even be infectious to us.

1. We don't know that with any certainty. It may end up being a "contest" to see which side can evolve an advantage over the other first before immunities are built up by both sides.

2. Mars life may be related. Studies suggest asteroids can blast spores betweens planets.

It's still pretty rare that diseases jump species here

But species jumpers also tend to be some of the deadliest. Livestock are notorious for producing whoppers.

Re:Return Sample?

[SatanicPuppy]

I don't honestly think there will be any evolutionary pressure, simply because there is no vehicle for it. In the case of livestock viruses, those viruses are passed around the animal populations for huge amounts of time before one manages to jump the divide. We live in close proximity to the livestock, so there is a good chance, given enough time, that a virus will mutate in just the right way, and that that mutation will happen in the right time and place to find a suitable host.

None of that applies to a theoretical martian virus that's got no growth vector and no suitable host animal that it's evolved to live in, that we like to hang out with. It would have to have us nailed the first time, no tests, no practice. That's pretty damn unlikely.

The asteroid thing is of course possible, but again pretty unlikely. In that scenario, it'd be more likely that we've already been infected with martian bacteria and have built up immunity than it is that our whole ecosystem is parallel to theirs, and their theoretical hostile bacteria are out there now, waiting.

Re:Return Sample?

[Geoffrey.landis]

You've been watching too much sci-fi...It's unlikely that something from such a wildly different evolutionary line would even be infectious to us. It's still pretty rare that diseases jump species here and everything on Earth is pretty closely related, genetically speaking.

Don't bother with that-- if Martian organisms are halophilic, they could not survive in a salt concentration as low as that in our bloodstream, or our oceans; they would literally fall apart.

...and if they're not halophilic, they wouldn't survive on Mars.

250 million?

[Tablizer]

Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth.

Earth cellular life evidence dates back to about 4 billion years if I remember correctly. Even some trilobite fossils date to around 530 million years ago. Perhaps they meant "250 million years since the formation of Earth"? Its a trick to make me RTFA to find out what they really meant.

No, not oldest evidence of life

[mck9]

No, these aren't the oldest known signs of life on earth. There are fossils way older than 250 million years. According to the article, this fuzz is the oldest known **biological material** on earth. Not the same thing.

Bad Summary

[algae]

Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth.

What the article actually *says*, is that the fibers themselves are 250 million years old, making them the oldest known biologically-produced material. There's obviously older evidence of life to be found on Earth.

While I'm nitpicking, "Earth" is capitalized, as it is a proper name.

Re:Bad Summary

[MightyMartian]

What the article actually *says*, is that the fibers themselves are 250 million years old, making them the oldest known biologically-produced material. There's obviously older evidence of life to be found on Earth.

I don't think that's quite accurate either. Certainly banded iron formations predate all of this by a couple of billion years. I guess cellulose may be the oldest surviving organic materials, but the evidence of life leaving behind different materials is much older than that.

Slug!

[Tablizer]

So my fantasy about pouring salt on a giant Mars Slug to save the astronaut colony still holds hope.

Re:Cellulose *variants*?

[Jodaxia]

Well basically any carbohydrate would be good evidence of life, however cellulose just happens to be very stable. (Think cotton shirts, cows chewing cud, and metamucil.)

http://en.wikipedia.org/wiki/Stromatolite

[sofar]

http://en.wikipedia.org/wiki/Stromatolite

Quote:

"The earliest stromatolite of confirmed microbial origin dates to 2,724 million years ago."

that's not the reason...

[sofar]

The real reason we want to explore Mars?

        Because we can

or, a variant after my favorite mountaineer (after the late Edmund Hillary):

        Because it's there

Stopping us from dreaming will make humanity dull and suicidal. Even though none of us might actually come to live the day that humans walk on the surface of Mars, doesn't mean that it is wrong to dream about it and start planning humanities future today.

Don't hide in your house from wonderful things that could be. Embrace the future and help make dreams come true!

Re:that's not the reason...

[ScrewMaster]

To talk about space exploration and ignore real problems is to talk like a thief and a fool. Both of which we have too many of already. Grow up already and enter the real world.

Well, it's a damned good thing the Queen of Spain didn't think like you.

Re:that's not the reason...

[sofar]

I've got news for you:

      We *are* exploring Mars and we have been doing so for a long time already.

Check your tax return this year and see how much money you paid into extraterrestrial research. You'll be surprised.

      "To talk about space exploration and ignore real problems is to talk like a thief and a fool."

I guess all little boys who want to be astronauts on this world are thieves?

Re:So what else is new? No life on Mars.

[MightyMartian]

If you want cold lifeless desert, go to Death Valley or Arabia or the Gobi. It's much closer. You get the same empty experience, and, most importantly, you don't cost your fellow taxpayers any money.

None of these, of course, are actually lifeless.

Why?

[rrohbeck]

What's the probability that life on another planet evolved the same type of chemistry and the same type of macromolecules?
If they found cellulose, I'd argue that it is from organisms that originated on earth. Now if they found (micro)fossils that are completely different from anything we know I'd listen up.

Re:Why?

[MightyMartian]

I honestly don't know enough about complex chemistry to answer any question like that. I would suspect, however, that for any carbon-based life, carbohydrates are going to be an absolute requirement for releasing and utilizing energy (ie. ATP). In that case, you're likely going to find related chemistry (starches, cellulose, etc.) in such ecosystems, even if they are unrelated to or only distantly related to life on this planet.

Now, of course, if life is silicon based, then you're right, you would have an entirely alien chemistry, and would have to look for very different things.

Re:250 million years

[PresidentEnder]

As others have said, the old cellulose isn't the oldest evidence of life on earth. It's the oldest biological material on earth. Fossils are just rocks, prettily shaped.

Re:So what else is new? No life on Mars.

[DMUTPeregrine]

They can't support human life. Yeah. Except, y'know, for the people that live there. Sure, they import water, but we could extract that at a higher energy expense from the air and deep watersheds. (Solar energy can provide that extra energy, while also providing shade under the solar panels to make cooling the water-storage area easier.) A self-sustaining community in an Earth desert is perfectly possible.
If the mars polar caps do contain water ice a human community on Mars is possible.
A self-sustaining human community would want to know about any possible infectious sources. A self-sustaining extraterrestrial human community is necessary to avoid probable pandemics, asteroid impacts, or other situations that would have extreme adverse effects on Earth-based population.
Therefore this research is in the public interest, and only pretentious, greedy twits with no concept of the future such as yourself can't see even the basic potential listed above. And there's lots more that can come out of such research, but, as with you, I'm not writing my doctorate thesis here.
P.S. Preview is your friend, as is

</i>

.