Fossils in Martian meteorite?

[bison]

It now appears much more likely that a Martian meteorite, found in Antarctica, contains evidence of fossils from the red planet. A new paper and the evidence to which it refers have been vetted for nearly three years, before being published.

The specimen under study, the meteorite called Yamato 000593 shows signs of tubular and spherical structures on a microscopic scale. The authors of the paper appear to have made a great effort to rule our geological and mineralogical processes. One receives the impression that if such structures were found in ordinary Earth rocks, they would be identified as fossils, with little ado. Link to paper:

http://online.liebertpub.com/doi/full/10.1089/ast.2011.0733

[Almagest]

That was an interesting and heady read, thanks bison. The authors are certainly cautious about it. I think this is just another piece of evidence on the growing pile for past life on Mars.

[scowl]

The most important paragraph I found from from my quick read.

This is the first report of purported indigenous carbonaceous matter in martian meteorite Y000593. This matter is embedded within spherules encased in layers of iddingsite compositions and embedded within iddingsite veins presumably formed by the action of liquid aqueous fluids on Mars (Gooding et al.,1991). Both the spherules and microtunnel features formed either prior to, or contemporaneously with, iddingsite and hence have a martian origin. It is possible the carbonaceous matter has an abiotic origin or origins derived from exogenous (cometary/asteroidal/interplanetary dust) sources (Flynn and McKay, 1989, 1990; Flynn, 1993, 1996) and/or through planetary process including magmatic and impact-generated gases (Zolotov and Shock, 1998, 1999). Alternatively, the spherules and associated carbonaceous matter may have biogenic origins because spherulitic features are similar in both size (0.1–0.5 μm) and shape to known terrestrial fossilized microbes reported in the range of 0.13–0.55 μm (Folk and Chafetz, 2000; Brigmon et al.,2008). The presence and distribution of carbon-rich areas with tunnel erosion patterns in iddingsite imply this matter is relatively insoluble, consistent with the geopolymer kerogen (Kim et al.,2006).

So yes, it sounds like the authors are cautious about making conclusions about this.

[Dark_Grey]

That is super exciting...alien life, no matter how old or simple

[scowl]

That is super exciting...alien life, no matter how old or simple

You realize that's not what the paper is saying.

[Grandpa Greenman]

We need a robot to go there and pick up some stuff and fire it back to us. Wouldn't get much payload back, I don't think, it will take some gas getting off Mars

[qxcontinuum]

We need a robot to go there and pick up some stuff and fire it back to us. Wouldn't get much payload back, I don't think, it will take some gas getting off Mars

LOosaurus

Don't we have already at least 4 rovers "living and breathing" currently on Mars?

[bison]

Unfortunately, none of our probes currently on Mars can send a rock or soil sample back to Earth. We depend for these on asteroid collisions with Mars. These can blast rocks into space, a few of which eventually fall on Earth. This is what is believed to have happened with the the Yamato meteorite. Blasted off Mars 12 or 13 million years ago, landed on Earth around 50,000 years ago; lying atop the ice, awaiting discovery, until a few years ago.

[JesseCuster]

LOosaurus

Don't we have already at least 4 rovers "living and breathing" currently on Mars?

Curiosity and Opportunity are the only active rovers on Mars at the moment.

[qxcontinuum]

I though spirit is still alive but can't move? I have also included the Phoenix robot but it seems that one is dead too....

Edited February 25, 2014 by qxcontinuum

[JimOberg]

Here's the story we just broke at NBC:

Tiny Blobs and Tunnels in Meteorite Revive Debate Over Life on Mars

http://www.nbcnews.com/science/space/tiny-blobs-tunnels-meteorite-revive-debate-over-life-mars-n38431

[Astra.]

An interesting read guy's...(links)

[bison]

The NBC news article quotes Everett Gibson, one of the researchers. He says that they next want to 'tear these carbon molecules apart'. The aim is presumably to find if the lighter isotopes of carbon predominate to such an extent that life processes are indicated. It's been known for some time that living things make more use of lighter carbon isotopes, than heavier ones.

[Imaginarynumber1]

We need a robot to go there and pick up some stuff and fire it back to us. Wouldn't get much payload back, I don't think, it will take some gas getting off Mars

I believe that the rover they want to launch in 2020 will do just that.

[JesseCuster]

I though spirit is still alive but can't move? I have also included the Phoenix robot but it seems that one is dead too....

Spirit sent its last communication in 2010 and after attempts to revive it the mission was officially cancelled in 2011.

Phoenix wasn't a rover but a stationary lander. It did't survive (and was never expected to) the 2008 Martian winter.

You're way out of touch with the current status of Mars missions!

[qxcontinuum]

Spirit sent its last communication in 2010 and after attempts to revive it the mission was officially cancelled in 2011.

Phoenix wasn't a rover but a stationary lander. It did't survive (and was never expected to) the 2008 Martian winter.

You're way out of touch with the current status of Mars missions!

Luckily we have you .. A man in a mission or a man with a mission...

Edited February 26, 2014 by qxcontinuum

[Crabby Kitten]

Mars is a really exciting adventure.

[scowl]

The NBC news article quotes Everett Gibson, one of the researchers. He says that they next want to 'tear these carbon molecules apart'. The aim is presumably to find if the lighter isotopes of carbon predominate to such an extent that life processes are indicated. It's been known for some time that living things make more use of lighter carbon isotopes, than heavier ones.

That's the next big question: how the heck did that carbon get in there?

[qxcontinuum]

That's the next big question: how the heck did that carbon get in there?

In the same time on mars has been detected in the past large quantities of methane which is usually an indicator of life. On earth more than 90 % of the methane in atmosphere is produced by living organisms according to scientists.

Edited February 26, 2014 by qxcontinuum

[scowl]

In the same time on mars has been detected in the past large quantities of methane which is usually an indicator of life. On earth more than 90 % of the methane in atmosphere is produced by living organisms according to scientists.

They now believe the detection of methane on Mars which was big news a couple years ago was false since it hasn't been corroborated by other observations. It should still be in the atmosphere but the rovers have not found any of it.

[bison]

The strongest evidence for fossils in the Yamato meteorite appears to be the tubular features in the rock and the size of the spherical bodies. The tunnels are undulating, like a river course, yet with an overall parallel trend. This is characteristic of erosion of organic material by bacteria, and not a geological process. The size of the spheres is around 300 nanometers, which is within the size range of known bacteria.

The suspected Martian microbes in the famous Allan Hills meteorite, which was in the news some years ago, were 20 to 100 nanometers in diameter. The fact that they appeared so small was a strong argument against their being fossils. That objection has been removed in this instance.

Edited February 28, 2014 by bison

[scowl]

The strongest evidence for fossils in the Yamato meteorite appears to be the tubular features in the rock and the size of the spherical bodies. The tunnels are undulating, like a river course, yet with an overall parallel trend. This is characteristic of erosion of organic material by bacteria, and not a geological process.

...that we have seen on Earth, therefore we can't exclude it since we know very little about Martian geology. For example Martian geology may have created microscopic tunnels of escaping gas. That would explain why the Yamato meteorite has small tunnels and the Allan Hills meteorite has larger yet similar tunnels. Morphology isn't a reliable method for detecting the presence of life.

If a rover finds a rock on Mars that has apparent biological features, do they have the ability to confirm that it didn't come from Earth?

[bison]

Since one can not disprove a negative, it's not possible to definitely state that the minute tunnels in the meteorite were not formed by escaping gas. The test of a scientific hypothesis is its probability, as against other possibilities. Is it more probable that the tunnels were produced by a known process of bacterial erosion, or by a form of gas diffusion for which we have no evidence?

Edited February 28, 2014 by bison

[scowl]

Yes. However since we have found absolutely no other evidence of life on Mars and we know virtually nothing about the geology of Mars, I would bet my life savings that we are looking at some type of geological process or some other process that we don't know about. These rocks are four billion years old, were impacted by a meteorite, spent an unknown amount of time in space and an unknown amount of time on Earth before they were discovered.

The tunneling has been seen in two meteorites, one that suggests that it could have been a biological process and another that doesn't suggest it was a biological process.

Morphology is the weakest form of evidence of life. Scientists have misinterpreted similar features in rocks here on Earth.

[bison]

If it were merely a matter of the shape of the structures (morphology) the case would be considerably weaker. We also have the carbon, not from carbonates, enrichment of those specific structures, relative to the rest of the meteorite, suggesting that they were once alive, or in contact with living things. We also have the presence of similar tunnels in another Mars meteorite and their absence from a control meteorite found in Antarctica, and not originating on Mars.