Methane-Eating Bacteria May Presage ET Life

asukasoryu sends along an intriguing piece in light of our recent discussion of possible signs of life on Saturn's moon Titan. "Researchers have discovered that methane-eating bacteria survive in a unique spring located on Axel Heiberg Island in Canada's extreme north. The subzero water is so salty that it doesn't freeze despite the cold, and it has no consumable oxygen in it. There are, however, big bubbles of methane that come to the surface. Lyle Whyte, McGill University microbiologist, explains that the so-called Lost Hammer spring supports microbial life, that the spring is similar to possible past or present springs on Mars, and that therefore they too could support life."

Re:As a wise fictional character said...

[biryokumaru]

From the title, I assumed you were quoting a book. So I googled it. Congratulations, you are your own top google hit [google.com].

Re:The problem with using extremophiles as models

[Daniel Dvorkin]

Interesting link, thanks! And I really hadn't realized that much stuff made it from here to there.

The question is, out of all that, how likely is it that an extremophile suitable for Martian conditions would be one of the passengers, and would land in a hospitable environment on Mars? The link doesn't address that directly, just noting that the Terrestrial organisms would have a good shot if they landed on Mars in a warmer, wetter age -- the problem there being that we don't know if there ever was such a time in Mars' history, or if so, if it lasted long enough to be significant on evolutionary timescales.

Again: extremophiles and the conditions in which they live, are almost by definition rare here on Earth. And conditions suitable for any Terrestrial life are obviously even rarer on Mars, and quite possibly always have been. I'm not saying it's impossible, just that it seems like awfully long odds.

Ask slashdot

[aBaldrich]

The story intrigued me, so I browsed wikipedia searching for the history of the atmosphere and atmospheric methane [wikipedia.org]. I find it very difficult to believe the idea of a chunk of Titan travelling all those years, carrying life and enough reserves of methane for the trip. And since methane used to be much more abundant in the atmosphere, isn't it possible that very old, earthy life forms lived off methane?

Re:The problem with using extremophiles as models

[EasyComputer]

The whole idea of cross contamination across the universe is what makes sense to me. Life in one of the "habitable" planets seeds life in another less "habitable" planet. As that newly arrived "life" thrives, it creates a hospitable environment for other types of organisms which might be arriving on some of the 100 tons of comet debris that enter into the planets atmosphere and/or evolving locally. Effectively the planet changes from a desolate wasteland into a place that can sustain life. Basically the life is what creates the hospitable planet, not the other way around. There was a program on a few days ago about this same idea a few days ago.

Re:The problem with using extremophiles as models

[QuantumG]

Glad you asked, cause I love educating random people on Slashdot who can't even be bothered clicking on the links I supply to them, or do their own research.

There's a whole class of bacteria that live inside rocks, they're called lithoautotrophic extremophiles. They suffer through extreme heat and pressures all the time. They have existed for billions of years. When a meteorite impacts the Earth a certain number of these fertile rocks are sent skyward.. the bacteria are protected from the radiation of space by the mass of the rock. Some portion of these rocks are captured by Mars and some even smaller portion are carried to the surface as meteorites. It's a big numbers game.

The speculation is that maybe these extremophiles are now making a living on the Mars service.. bacteria moving from one rock to another isn't that big a stretch of the imagination. Some of them may even make the return trip.

Re:No viable Mars-Earth rock exchange happening no

[QuantumG]

Well that's the controversial part.. almost every instrument that has been sent to Mars to search for life, actually made it to the surface safely, and managed to turn on, has returned positive results of life on Mars. Every time this has happened there has been denials.. as there's always a malfunction or non-biological explanation that can be used to explain the data. Similarly, every instrument that has returned a negative result for life on Mars (and there's less than have returned positive results) have been shown to be unable to detect life in the extreme locations of Earth, whereas a microbiologist with a $5000 microscope and some plastic slides can find life in these same areas without any trouble. Which is why the question of life on Mars remains open.. and probably will remain open until a sample return mission gives a positive result, and maybe even then not until the first extraterrestrial genome has been sequenced.

As for multi-cellular organisms, for all we know there's plants, moss, or fungi in caves on Mars.. but we'd never know because we've never explored any of them.
 

Re:The problem with using extremophiles as models

[blhack]

Even on a cosmic timescale, that isn't very often. The earth is about 4.5 billion years old, no? Life on earth is, what, 3.5 billion years old (at least these are the earliest fossils we can find)?

So if this happens once every 5 million years, that is still only 1000 times that we have traded rocks with Mars.

That's a lot, but if you're talking about the chances of those rocks containing some absurdly rare strain of bacteria that can exist in an environment very much unlike that of the majority of this planet, it starts looking pretty damn unlikely.

Cosmic time scales or not, one every 5 million years is certainly not "constantly".