Protein discovered inside a meteorite

[rolph]

A team of researchers from Plex Corporation, Bruker Scientific LLC and Harvard University > has found evidence of < a protein inside of a meteorite.

there is a mismatch between the title of that article and the level of confidence these researchers were expressing.

the preprint is here:

https://arxiv.org/abs/2002.11688

[eindiran]

I mean, the first sentence of the preprint is "This paper characterizes the first protein to be discovered in a meteorite." The Significance section states that "[the preprint] is the first report of a protein from any extra-terrestrial source." And they claim that their evidence[0] that the protein is not a terrestrial contaminant is quite strong, so I would say that the confidence level of the researchers matches the title exactly.

[0] For example, from the conclusion: "The average molecular deuterium excess above terrestrial is (25,700 ± 3,500)%, or a D/H ratio of (4.1 ± 0.5) x10^-3, comparable to cometary levels, interstellar levels and also equal to the highest prior report in micro-meteorites."

[jessaustin]

One of the cites at the link is a previous paper on similar investigations of one of the same meteorites plus one other, that was published in 2015 in Meteoritics & Planetary Science, a journal with a long publication history. That paper is cited by two other papers from different authors. [0]

At some level, these researchers seem to be doing basic chemistry. Maybe they're not characterizing the implications correctly or maybe they haven't controlled contamination, but if proper research discovered extraterrestrial protein it would probably generate papers that looked like these.

[0] https://scholar.google.com/scholar?cites=8914643017753968792...

[driverdan]

It's bad writing. They also have this gem:

> but once the findings are confirmed...

which should be "but if the findings are confirmed"

[shadowgovt]

I need to make time to ask someone to ELI5 to me how this research is done without contaminating the sample with terrestrial-originated protein. The meteorite was on Earth for some time, and bacteria are staggeringly invasive little bugs.

I believe they successfully avoid contamination, but I have no idea how.

[rolph]

sanitize a small sample then crack it open under cleanroom conditions to obtain an assumed pristine sample.

[edit] This is the full pdf below, if you look at page 2, you will see how they generated prepared and analyzed the sample

https://arxiv.org/pdf/2002.11688 [PDF]

and this is the meteoritic report for the subject:

https://www.lpi.usra.edu/meteor/metbull.php?code=95

the thing with structured peer review is that noone knows it all , and a team of specialists [review commitee] are much more powerful than a team of generalists, to the end of revealing any artefacts of procedure, or hair splitting levels of knowledge regarding metalo-organic chemistry that could explain abiotic process that would produce amino acid polymerization.

[shartshooter]

I read a comment on HN or Reddit a while back about how some molecules were found in a meteorite that were left-handed where every molecule on earth is right-handed or something to that extent.

If my memory serves it was as if molecules fit together like a lock and key except this molecule's key/lock combo was inverted.

Apologies if I'm bungling it up but it felt as though it was significant. As if the molecule found was unlike any molecule on earth due to its lock/key orientation.

[anorwell]

I think the homochirality of amino acids might be what you're referring to:

https://en.wikipedia.org/wiki/Chirality_(chemistry)#In_bioch...

"The origin of this homochirality in biology is the subject of much debate.[12] Most scientists believe that Earth life's "choice" of chirality was purely random, and that if carbon-based life forms exist elsewhere in the universe, their chemistry could theoretically have opposite chirality. However, there is some suggestion that early amino acids could have formed in comet dust. In this case, circularly polarised radiation (which makes up 17% of stellar radiation) could have caused the selective destruction of one chirality of amino acids, leading to a selection bias which ultimately resulted in all life on Earth being homochiral."

[jleahy]

You are talking about chirality. Biologically produced molecules are all of the same "handedness", but molecules produced by other means (normal chemical reactions) tend to have 50/50 chance to be either handedness (although selective reactions are possible).

So you'd expect to see both at a 50/50 ratio in a meteorite, if you see any at all. That's just chemistry.

[kens]

Interestingly, the protein described in the article is made out of glycine, the only amino acid that doesn't have handedness (i.e. it is achiral). So you can't tell if this protein is terrestrial or not based on its handedness.

[westmeal]

Proponents of panspermia are pretty happy about this finding I bet.

[qubex]

To be perfectly honest, you’ve drawn my attention to an ambiguity I had never before noticed: does panspermia’s hypothesis that “life” came from space require that life arrive fully formed and functional, or does it advocate that complex organic chemicals arrived from space and assembled on earth into a working configuration?

I have always found the idea of panspermia to be a bit of a cop-out as it totally sidesteps the problem of abiogenesis: it’s all fine and well to say “life came from space” but you still need to explain how life arose in space to begin with.

[Mountain_Skies]

While I have no objection to panspermia being possible, if it were true, it would be a significant hurtle added to the search for the origins of life. We would know how life on Earth started, but until we expand out into the galaxy, understanding the origins of the life that seeded Earth would be essentially unknowable.

[tartoran]

"The team's paper has not yet been peer reviewed"..

[forinti]

It might hurt humanity's pride if this material turns out to be dejects spewn from passing spaceships.

[throwGuardian]

The impact of a collision is so devastating that any life surviving it is unlikely. Unless such life can endure such extreme conditions, in which case, it would exist on such inhospitable conditions as on Venus

[UI_at_80x24]

So far sugars, and amino acids have been found in both comets & gas clouds. BUT to find this protein is the slam-dunk, holy-shit they were right, proof that Panspermia is how we got here, and there _MUST_ be life in other parts of the universe.

[VT_Dude]

Before we even get into the role of expert peer reviewers, does the article pass basic tests of authenticity, let alone extraordinary claims requiring extraordinary proof?

The third author of the referenced paper does have a page at Harvard, here: http://www.people.fas.harvard.edu/~mcgeoch/index.html where she says she is at the "Department of Molecular and Cellular Biology, Harvard University" but she's not listed as faculty in that department here: https://www.mcb.harvard.edu/faculty/faculty-profiles/

Could be a student... but do a search for Malcolm. W. McGeoch, Sergei Dikler, Julie E. M. McGeoch from Plex Corporation, Bruker Scientific LLC and Harvard University

and you will start to wonder if these people even know their names have been used in this article. Shame on phys.org for not calling the author for a quote or doing any other legwork to convince me this is anything other than a UFO hoax or the output of a paper-writing AI. It could be, but ...journalist please.

[T-A]

You can look up McGeoch, Julie here:

https://www.directory.harvard.edu/

Associate of the Department of Molecular and Cellular Biology.

Previous papers on arxiv (just click the author name on the abstract page):

https://arxiv.org/search/astro-ph?searchtype=author&query=Mc...

I am all for healthy skepticism, but insinuating a hoax based on an ad hominem without even spending a few seconds to do a quick check is not.

[ampersandy29]

Some cursory search shows papers published by Julie E. M. McGeoch on related topics over the last 30 years, many of which are also co-authored by Malcom McGeoch of Plex Corporation, who I assume is of some relation (significant other or relative). I admittedly don't know a ton about academic publishing, but from my outside position, it seems unlikely that this report is fraudulently attributed—though it's certainly possible that I'm missing something.

[MockObject]

They believe that this meteorite is native to our solar system, so it's not a candidate for panspermia from anywhere interesting.

[aetherspawn]

That’s probably what should interest us the most - the article says the protein arrangement is previously unknown but functional (?).

[briga]

You don't think it would be interesting to discover non-Earth proteins within our solar system? At the very least, this finding would be a pretty good indicator that proteins occur naturally outside of our solar system as well.

[n0rbwah]

Life arising anywhere other than earth would be a big deal.

[DrOctagon]

Crunchy on the outside, chewy protein center.

[aldoushuxley001]

Seems like this should be bigger news

[gipp]

It's a potentially pretty big deal for understanding extraterrestrial chemical processes and estimating the likelihood of life, but to be clear this isn't anything like actual evidence of alien life.

It's a bit of a stretch to call this a "protein" TBH. The protein part is composed of only glycine, so there's really no information (e.g. DNA) required to synthesize it, just glycine and a chemical environment that would cause it to polymerize. The caps at either end are not protein components at all, as the article mentions, and protein backbones on Earth are never cyclic afaik.

But, it's still a very complex organic molecule ofc, which is very significant on its own, and its similarity to protein is evidence that protein-based life could be more common.

[nraynaud]

I think we should give it time, look for other evidence, and slowly solidify the idea.

[lxmorj]

Don’t build my app

[naynay]

just mix with all the ones that were already

[rafaelvasco]

Nothing to be surprised about. The seeds of Life are everywhere. Earth is just a tiny microscopic point compared to the infinity of the Universe;

[ouid]

An observer observing themselves is not data.