Organic matter on Mars? New research suggests chloromethane not due to contamination from Earth

A new research paper was published today in Scientific Reports (from the publishers of Nature) which suggests that chloromethane found by the Curiosity Rover and by a previous Viking mission may not be due to contamination from Earth as had been previously believed.

The announcement of the new research paper on ScienceDaily.com is a bit lighter reading for those of us who are not organic chemists, so I will provide quotes from Science Daily's article but also link to the actual research paper at the bottom of this post.

Is there organic matter on Mars? Chloromethane not due to contamination from Earth, research suggests

Organic matter recently detected by NASA's robotic rover Curiosity is probably not due to contamination brought from Earth as researchers originally thought. A team of German and British scientists led by geoscientist Prof. Dr. Frank Keppler from Heidelberg University now suggests that the gaseous chlorinated organic compound -- chloromethane -- recently found on the Red Planet most likely comes from the soil of Mars, with its carbon and hydrogen probably deriving from meteorites that fell on the planet's surface. This assumption is supported by isotope measurements made by the scientists in which they replicated some of the Mars lander experiments. In these investigations, samples from a 4.6 billion old meteorite that fell in Australia in 1969 were used.

...the NASA Curiosity rover... conducted investigations on Martian soil. Upon heating soil samples simple organic molecules were detected and identified by on-board measurement systems. One of the substances detected was chloromethane, which contains carbon, hydrogen and chlorine atoms. In the opinion of the NASA experts, however, this compound could have been formed during the soil heating experiments by a reaction between perchlorates in Martian soil and an on-board chemical. Thus, even though the chlorine in the chloromethane comes from Mars, the carbon and hydrogen were considered to have been brought to Mars by the Curiosity rover. Interestingly this kind of organic material had also been identified in earlier experiments during the Viking mission in 1976, but the compound was considered a terrestrial contaminant.

Arken and Calgarian had threads back in 2011 and 2012 about Viking finding this more than 30 years ago:

Viking Found Organics on Mars, Experiment Confirms!

Viking robots found life on Mars in 1976, scientists say

And there may have been threads about Curiosity finding chloromethane, though a search on ATS didn't turn them up. But this is new research just published today, and the new research provides an interesting update and perhaps confirmation that the carbon and hydrogen in the chloromethane were not from contamination from Earth after all:

The German-British team of scientists led by Prof. Keppler... investigated whether there could be another explanation for the observations of chloromethane on Mars. They assumed that the gaseous chlorinated organic compound is indeed derived from Martian soil, but that its carbon and hydrogen are provided by meteorites. To support their hypothesis, the researchers examined samples from a 4.6 billion years old meteorite that fell on earth in 1969 near the Australian city of Murchison. According to Prof. Keppler this meteoritic material contains two per cent carbon. Space experts assume that a relatively large amount of micrometeorites with a similar composition to the one of Murchison fall on the surface of Mars each year.

When Frank Keppler and his colleagues heated the Murchison meteoritic matter in the presence of chlorine they observed chloromethane. "The ratio of heavy to light carbon and hydrogen atoms, known as the isotopic fingerprint of a gas, clearly shows that the organic material has an extraterrestrial origin," Prof. Keppler says... "Hence chloromethane which was found by the two separate Mars missions could be formed by the Martian soil, and the carbon and hydrogen would have their origin in the micrometeorites that rain down on Mars," explains Prof. Keppler. "However, it cannot be ruled out that microorganisms which might have been living on the planet some time ago might have provided a fraction of the organic matter." The Heidelberg scientist assumes that in future Mars missions the isotopic fingerprint of the chloromethane could determine whether its origin is from organic material that is indigenous to Mars, was deposited by meteorites or is contamination from the landers sent from Earth.

It's not conclusive, since it's based on the use of a meteorite rather than soil on Mars. But it is pretty interesting research.

Access to the PDF of the research paper is currently open on Nature.com and you can read the PDF here:

Chloromethane release from
carbonaceous meteorite affords new insight into Mars lander findings (PDF)

You can make it by boiling methanol, sulfuric acid, and sodium chloride so it could just be something innocent.

It would be some sort of rock plankton wouldn't it? Not really all that elaborate as a lifeform but it is still alive.

It won't be "Organic" matter for long, once MONSANTO gets into space.

a reply to: ikonoklast

After so many false alarms lately about stuff on Mars (the latest was a hoax thread about fish bones), and now threads about stuff on the comet, it's good to get some news which has potential. I'll follow this with interest, thanks.

originally posted by: Aleister
a reply to: ikonoklast

After so many false alarms lately about stuff on Mars (the latest was a hoax thread about fish bones), and now threads about stuff on the comet, it's good to get some news which has potential. I'll follow this with interest, thanks.

I believe they already know there is life on Mars...when will they finally feel we are in a need to know position that is the only question.

a reply to: Aleister

You're welcome. I thought it was nice to see this come out after the previous debates on whether possible past findings were due to contamination from Earth. I'm hoping that we will learn some interesting things from this and from the landing on the comet as well.

Pity the new research doesn't indicate that the chloromethane came from living organisms, but from carbon and hydrogen introduced to the planet by meteorites. It's not really supporting the 'life on Mars' hypothesis.

'A godawful small affair,' some might call it...