Extraterrestrial organic matter preserved in 3.33 Ga sediments from Barberton | Hacker News Reader

Extraterrestrial organic matter preserved in 3.33 Ga sediments from Barberton

sciencedirect.com

58 points_cereal19 comments

The article uses the word "organic" in a highly technical manner, meaning chemical compounds that contain carbon, and of course we already know that space is filled with that sort of thing. It does NOT mean "organic" in the casual sense of originating from something alive.

They do mean it that way, though. They mention the possibility of extinct life on Mars in the last paragraph highlight.

They mention their finding "highlights the challenges in store for the research for trace of extinct life in Mars.", which seems different to me.

"Organic chemistry" is a very common usage of organic in that "contains carbon" sense.

For sure, it's entirely appropriate for the abstract, but it bears pointing out to an audience who might not be familiar with that usage.

As a layman I guessed as much, but wasn't positive. Clickbaity title.

Not really - makes a ton of sense if you're an organic chemist.

I’m not an organic chemist or a chemist of any sorts, and the headline didn’t phase me at all or stick out as clickbait. I knew exactly what it meant though to be fair “o chem” was a common course among my friends majoring in things like bio-*.

Typical layman response, expecting niche articles to be dumbed down to them

Is there any organic chemical that can only be produced by life? Not even sure that’d be possible.

Depends on your personal tolerance for the complexity indicated by the word "chemical". The presence of "deoxyribonucleic acid" on its own does not prove life, as that term covers simple cases of it that could conceivably naturally occur. However, if you've got a multi-million base pair chain of the stuff, wrapped up in chromatin, and bespeckled with all manner of useful-looking biochemical doohickeys attached to it, I'm willing to say that's definitely indicative of life. Is that a "chemical"? I'd certainly call that a "molecule" that could only be produced by life.

I've read that this question can be answered by looking at the chirality of the chemical(s) in question. If the levorotatory and dextrorotatory isomers are unevenly distributed, that's a hint that the substance originated in biological processes.

Not sure if that's still the current thinking, or if it ever was, but I found it interesting when I ran across it.

In principle or practice? There a large number of secondary product compounds produced by microorganisms that have never been synthetically synthesised, but in theory they all could be.

If you want to prove that an organic compound has come from a living system you look for carbon isotope enrichment or depletion - more C12 and less C13 than found in the environment.

Some analysis: https://www.sciencealert.com/traces-of-extraterrestrial-orga...

Still scanning but I think one must keep in mind the distinction between "organic matter" and "biological matter", organic is a broad category that involving a complex array of chemicals that aren't necessarily generated by living things. Biological material or similar terms refer to stuff that definitely is or was once alive.

https://en.wikipedia.org/wiki/Organic_matter

https://en.wikipedia.org/wiki/Biogenic_substance

I think the paper stated that the organic matter was similar to those found in some Archaean fossils in the area and other parts of the world, so it seems to be an interesting find

Of course it’s all too easy for a layman such as myself to read too deeply into things and draw unfounded conclusions about the origins of life. And if I recall, the rock is newer than the oldest known fossils, so I’ll keep a little distance on that conclusion for now

But it was pleasant to read about the earliest known fossils, so that’ll be my current takeaway on this

Just more evidence that life on earth may have been helped along by all this carbon containing/organic matter deposited via meteorites.

Very unlikely, as the concentrations would be quite minute. Nick Lane expands on this in "The Vital Question" book.

That's meaningless. The Earth coalesced from supernova remnants, which included organic compounds, but that doesn't imply living organisms.

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