Date: 4/12/2014 11:51:25
From: Cymek
ID: 639018
Subject: Tissint meteorite could be proof of life on Mars, study claims

I notice that the evidence presented for the existence of life on Mars is always very tenuous and open to interpretation either pro or con. This research is an example it’s not overly convincing from what I read, we do seem almost desperate to prove life once existed on Mars and will lean it the favour it did which is understandable. I’d have thought the best approach would be undeniable proof (if such a thing exists) that we know for sure was created by the process of life not some geological or other process.

http://www.news.com.au/technology/science/tissint-meteorite-could-be-proof-of-life-on-mars-study-claims/story-fnjwlcze-1227144260703

AN INTERNATIONAL team of researchers say they’ve found evidence of biological activity inside a meteorite that fell to Earth from Mars three years ago — in other words, possible evidence that there was once life on the red planet.

But other scientists aren’t convinced.

The meteorite in question is the “Tissint” specimen, which famously fell on the Moroccan desert on July 18, 2011.

As the team of researchers — including scientists in China, Japan, Germany, and Switzerland — report in a new paper, chemical, microscopic, and isotope analyses show traces of organic carbon within tiny fissures in the space rock, and that the carbon had to have been deposited before the rock left Mars.

“I’m completely open to the possibility that other studies might contradict our findings,” Dr. Philippe Gillet, director of the EPFL Earth and Planetary Sciences Laboratory in Lausanne, Switzerland and a co-author of the paper, said in a written statement. “However, our conclusions are such that they will rekindle the debate as to the possible existence of biological activity on Mars — at least in the past.”

And contradiction wasn’t long in coming.

As Dr. Marc Fries, a scientist with NASA’s curation office at the Johnson Space Center in Houston who was not involved in the meteorite research, told The Huffington Post: “The research group claims that this carbonaceous material is evidence of past life on Mars. I do not agree, and it is not the current consensus of the scientific community that their claim is valid.”

Fries said the meteorite could have been contaminated with carbon from terrestrial sources, even if the carbon did come from Mars.

“A biological origin is not the only possible explanation for the carbon found in Tissint,” he said in the email. “Other possibilities include volcanic and/or hydrothermal activity on Mars which could permeate Tissint with carbon-bearing fluids … Regardless of whether this particular meteorite contains evidence of life, the implications are more complicated than any simple yes or no answer to whether there is or was life on Mars.”

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Date: 4/12/2014 13:21:21
From: wookiemeister
ID: 639097
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

The Martian atmosphere never changed its character in line with an explosion of life

The chances of life coming from mars is a million to one

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Date: 4/12/2014 13:22:59
From: dv
ID: 639102
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

wookiemeister said:


The Martian atmosphere never changed its character in line with an explosion of life

Well it clearly had a fairly heavy atmosphere at some stage.

But yes, take this analysis with a grain of salt in the OP. These are not definitive markers.

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Date: 4/12/2014 13:24:18
From: Bubblecar
ID: 639106
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

wookiemeister said:


The Martian atmosphere never changed its character in line with an explosion of life

The chances of life coming from mars is a million to one

I wouldn’t put such a precise figure on it, but wouldn’t be at all surprised if there was never any life on Mars.

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Date: 4/12/2014 13:24:29
From: wookiemeister
ID: 639107
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

dv said:


wookiemeister said:

The Martian atmosphere never changed its character in line with an explosion of life

Well it clearly had a fairly heavy atmosphere at some stage.

But yes, take this analysis with a grain of salt in the OP. These are not definitive markers.


Listened to a talk about mars at an astronomy club thing

The atmosphere had never changed in its composition

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Date: 4/12/2014 13:29:00
From: dv
ID: 639117
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

wookiemeister said:


dv said:

wookiemeister said:

The Martian atmosphere never changed its character in line with an explosion of life

Well it clearly had a fairly heavy atmosphere at some stage.

But yes, take this analysis with a grain of salt in the OP. These are not definitive markers.


Listened to a talk about mars at an astronomy club thing

The atmosphere had never changed in its composition

It has been established that there were oceans on Mars, and their existence means that the atmosphere must have been considerably denser than it currently is (large permanent liquid water bodies can’t exist at the current low pressures).
The former composition is not well known though some of the isotope work from the next lander should answer some of those questions.

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Date: 10/12/2014 05:52:49
From: mollwollfumble
ID: 642651
Subject: re: Tissint meteorite could be proof of life on Mars, study claims

> As the team of researchers — including scientists in China, Japan, Germany, and Switzerland — report in a new paper, chemical, microscopic, and isotope analyses show traces of organic carbon within tiny fissures in the space rock, and that the carbon had to have been deposited before the rock left Mars.

The original announcement paper on possible signs of life in ALH 84001 is well worth a read.
McKay, David S.; Gibson Jr, E. K. et al. (1996). “Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001”. Science 273 (5277): 924–930. Bibcode:1996Sci…273..924M. doi:10.1126/science.273.5277.924. PMID 8688069.
The original announcement gave four or five separate circumstantial pieces of evidence including, IIRC, traces of organic carbon. Not one of these was convincing in itself but all pointed in the same direction.

The Wikipedia page is Allan_Hills_84001

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