SD: Could Life Survive on Mars?

[bystander]

Could Life Survive on Mars?
Science Daily - 05 June 2010

Researchers at McGill's department of natural resources, the National Research Council of Canada, the University of Toronto and the SETI Institute have discovered that methane-eating bacteria survive in a highly unique spring located on Axel Heiberg Island in Canada's extreme North. Dr. Lyle Whyte, McGill University microbiologist explains that the 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.

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, which had provoked the researchers' curiosity as to whether the gas was being produced geologically or biologically and whether anything could survive in this extreme hypersaline subzero environment. "We were surprised that we did not find methanogenic bacteria that produce methane at Lost Hammer," Whyte said, "but we did find other very unique anaerobic organisms -- organisms that survive by essentially eating methane and probably breathing sulfate instead of oxygen."

It has been very recently discovered that there is methane and frozen water on Mars. Photos taken by the Mars Orbiter show the formation of new gullies, but no one knows what is forming them. One answer is that there could be that there are springs like Lost Hammer on Mars.

"The point of the research is that it doesn't matter where the methane is coming from," Whyte explained. "If you have a situation where you have very cold salty water, it could potentially support a microbial community, even in that extreme harsh environment." While Axel Heiberg is already an inhospitable place, the Lost Hammer spring is even more so. "There are places on Mars where the temperature reaches relatively warm -10 to 0 degrees and perhaps even above 0ºC," Whyte said, "and on Axel Heiberg it gets down to -50, easy. The Lost Hammer spring is the most extreme subzero and salty environment we've found. This site also provides a model of how a methane seep could form in a frozen world like Mars, providing a potential mechanism for the recently discovered Martian methane plumes."

New Discovery Supports Possibility of Microbial Life on Mars
Universe Today - 04 June 2010

The discovery of methane-eating bacteria in a very unique region of Canada's extreme north supports the theory that similar organisms could be on Mars. Researchers have found methane-eating bacteria in a cold, methane filled spring located on Axel Heiberg Island in Canada, and say the spring is similar to possible past or present springs on Mars, and that therefore they too could support life.
...
The discoveries of methane and frozen water on Mars, along with recently formed gullies are similar to what is occurring on Axel Heiberg Island. The methane on Mars is quite intriguing since the short-lived gas is obviously being replenished in some way. But just the fact that methane is on Mars could mean the planet could support life.

Microbial characterization of a subzero, hypersaline methane seep in the Canadian High Arctic.

• The ISME Journal, 06 May 2010; DOI: 10.1038/ismej.2010.57

[Ann]

A very interesting post, Bystander.

Personally I'm highly skeptical of attempts to "antropomorphize" the universe, or to prove that other planetary bodies are so much like the Earth (even though they obviously aren't like the Earth) that they must be like the Earth in such a way that they must be life-bearing, like the Earth.

So in my opinion, if the Earth and Mars were highly similar, then the presence of methane on Mars might very well mean exactly what it means on the Earth. Indeed, even though Mars and Earth are so dissimilar, the presence of methane on Mars could men exactly what it means on the Earth. It's possible.

However, is it likely that there is life on Mars? Admittedly that question is very difficult to answer, since we know so little about how life arose on the Earth (actually we know nothing about it).

One obvious difference between Earth and Mars, however, is that there is so very much life on the Earth, whereas on Mars, if there is life at all, there can only be small quantities of it. In terms of tons of biomass, the Earth must have tens of thousands as much of it as Mars can have even in a best-case scenario.

Now consider that life on Earth has come quite close to extinction on several occasions during life's circa three billion year esistence on the Earth. The fact that life has always bounced back may have something to do with the fact that there has been so much of it almost from the beginning. On the Earth, even the greatest catastrophes our planet has suffered have never been enough to kill all life here. Therefore it has always been possible for life to stage a comeback.

If Mars has never had more than a rather small biomass, made up of comparatively few individuals, these Martian life forms may have been extremely vulnerable to such things as catastrophic climate changes. If a hundred tons of biomass on Mars died because of some catastrophe, there may have been little or no life left to make a comeback.

Yes, there are life forms that thrive in extreme conditions on the Earth. It could be that life has tried to inhabit these extreme niches on the Earth over and over again and failed until there finally were some life forms that got it right.

It doesn't seem likely that life would get that many chances on Mars.

Ann

[BMAONE23]

Life evolved on Earth as directed by changing conditions presant at the time of its existance, it did what it needed to in order to survive, it morphed. The same thing could have happened on any planetary body (planet or moon) that possesses the basic ingredients for life (gaseous atmosphere and/or source of hydration, relative safe havens) Bacterium have evolved on earth (protected by a large magnetic field and UV absorbing gasses) to be intolerant of higher levels of UV. If they were to have started out in a differing situation, they may have evolved to be high level UV tolerant and could therefore survive the rigors of Mars. So if it started there, it could evolve to thrive there.