New paper appeared on the Arxiv where scientists are reporting to have discovered the first protein not having a terrestrial origin. It needs to be stated that if this result stands up to scrutiny(other labs will probably have to confirm these results), it likely not a product of life, but of abiotic chemistry that happens inside carbonaceous chondrites.

http://astrobiology.com/2020/02/hemolithin-a-meteoritic-protein-containing-iron-and-lithium.html

This paper characterizes the first protein to be discovered in a meteorite. Amino acid polymers previously observed in Acfer 086 and Allende meteorites [1,2] have been further characterized in Acfer 086 via high precision MALDI mass spectrometry to reveal a principal unified structure of molecular weight 2320 Daltons that involves chains of glycine and hydroxy-glycine residues terminated by iron atoms, with additional oxygen and lithium atoms.

Maybe good ammo to use against the "no abiogenesis possible without Gawd" brigade, this.

Well at least it's a good piece of evidence against the claim that complex organic molecules can't form without intelligent design. I wouldn't claim this shows life can originate in meteorites or something like that, just that there are no in-principle barriers to the formation of complex systems by just "dumb" physics and chemistry.

Yup, that's what I meant to suggest. At first I was like "duuuh, how could life get into a metiorite?" then read the OP, then the intro to the wiki page on proteins, as TBH the idea of an abiotic protein didn't sit well with me. It does now though

Edit: hang on, is this an "organic" molecule? Semantic minefield around here...

I haven't read the article yet, but organic merely means containing carbon.

Yes, organic chemistry is really just named that due to some historical convention. There is lots of non-biological organic chemistry. Generally organic chemistry just refers to chemistry involving carbon.

Sorry, where were these rocks found?

In a meteorite called Acfer 086 (a CV3 carbonaceous chondrite Allende meteorite) found in Algiers in 1990.

According to this: https://www.vice.com/en_us/article/z3bw ... sts-report

The protein found through mass spectrometry in the meteorite is called hemolithin and is composed primarily of glycine, hydroxyglycine and amino acids. It also contains atoms of oxygen, lithium and iron in a previously unobserved arrangement. The deuterium/hydrogen ratios are exceptionally high and not found in such ratios anywhere on Earth. The only place we've witnessed them is in long period comets. The conclusion then is that the protein formed in an interstellar molecular cloud perhaps tens of billions of years ago.

it's old, couldn't the organic material come from a contamination?

Svartalf wrote:it's old, couldn't the organic material come from a contamination?

From the article Spearthrower just linked to in the post above yours:

To make sure that the protein wasn’t simply contamination from an earthly source, the researchers calculated its deuterium/hydrogen (D/H) ratio, which is a value that contextualizes the origins of materials. The results revealed “very high extraterrestrial D/H ratios,” according to the study, suggesting that the protein was formed in the proto-solar disc or perhaps even earlier, in interstellar molecular clouds that existed long before the Sun’s birth.

Given that some meteorites contain stardust grains that are older than our solar system, it is not outlandish to imagine that they could also preserve proteins that date back billions of years.

Svartalf wrote:it's old, couldn't the organic material come from a contamination?

Its literally inside a rock.

To contaminate the inside of a rock, it would need to happen at rock formation.

It's also like none that we've ever seen, and comprises atoms that are not found in such ratios on Earth.

So no, not really.

It has a very unusual composition and structure not seen in any known biological protein. That doesn't of course mean it couldn't possibly be contamination, but several lines of evidence points to it being indigenous to the meteorite. First of all it is made of polymers of glycine, the most abundant amino acid in carbonaceous chondrites. Then the fact that the chains of glycines are attached at both ends to a strange mineral structure containing iron, sulfur, oxygen, and lithium atoms. And then finally the isotopic composition is consistent with the source material of the meteorite, as opposed to deriving from a terrestrial source of organic material.