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Protein discovered inside a meteorite

phys.org

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Re: Protein discovered inside a meteorite

#51

Post by lovemenot »

Mountain_Skies wrote: post #20
westmeal wrote: post #2

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

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.

Assuming panspermia is correct, we could just continue to improve sampling of stuff coming here. Also sampling earth-originated organic materials from some distance away. This could give us some pretty good data on variety, density, duration.

Under this assumption I'd most like to estimate the number of discrete seeders in our vicinity and their interconnectedness.

Re: Protein discovered inside a meteorite

#52

Post by jessaustin »

rolph wrote: post #48
jessaustin wrote: post #40

Earlier quoted context omitted.

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 correct…

>> At some level, these researchers seem to be doing basic chemistry what it looks like to me is that a couple just received a good research grant set up a laboratory in started putting it to good use. we need to find these polymers on samples that are still off world, or we need to be able to demonstrate such polymerization in an environment mimmicking conditions off planet.

"Basic" is not meant to be derogatory. They're chemists; that's what they should be doing. It would be more troubling if their results came from "novel" chemistry.

Re: Protein discovered inside a meteorite

#56

Post by throwGuardian »

jleahy wrote: post #45
shartshooter wrote: post #42

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…

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.

Why 50/50? It should take on the statistics of causations of chirality. And based on that, one might be able to guess the exact location and orientation of the meteorite when these chemicals were formed

Re: Protein discovered inside a meteorite

#57

Post by throwGuardian »

westmeal wrote: post #2

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

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

Re: Protein discovered inside a meteorite

#59

Post by dekhn »

anorwell wrote: post #44
shartshooter wrote: post #42

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…

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 opposit…

I've also heard some scientists say that parity breaking could explain the origin of homochirality. Personally, I'm happier with the "random chance" hypothesis.

Re: Protein discovered inside a meteorite

#60

Post by dekhn »

JoeAltmaier wrote: post #38
svachalek wrote: post #36

Earlier quoted context omitted.

It's only a cop-out if you try to use it to explain the origin of life in general, not just on Earth. Life arose very quickly on Earth, almost as soon as it was capable of surviving, so it raises the interesting question: were we just lucky, or is it easy to spawn life, or did it come from elsewhere? The answer creates very different pictures for what Earth-like planets elsewhere in the galaxy actually look like.

I'm always confused by that. So there's only one form of life possible? Otherwise life may have arisen before, been wiped out when Earth changed, and life arose again. We may be just the latest in a long series of life forms.

theoretically possible but there is no evidence to suggest this. Weighing the various hypotheses, most people would suggest the "simpler" (fewer wipeout/arise events) hypothesis, given the assumption that life arising is considered very rare.
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