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Did comet impacts jump-start life on Earth?

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https://phys.org/news/2019-06-comet-impacts-jump-start-life-earth.html

Comets screaming through the atmosphere of early Earth at tens of thousands of miles per hour likely contained measurable amounts of protein-forming amino acids. Upon impact, these amino acids self-assembled into significantly larger nitrogen-containing aromatic structures that are likely constituents of polymeric biomaterials.

That is the conclusion of a new study by Lawrence Livermore National Laboratory (LLNL) researchers who explored the idea that the extremely high pressures and temperatures induced by shock impact can cause small biomolecules to condense into larger life-building compounds. The research appears in the journal Chemical Science and will be highlighted on the back cover of an upcoming issue.

Glycine is the simplest protein-forming amino acid and has been detected in cometary dust samples and other astrophysical icy materials. However, the role that extraterrestrial glycineplayed in the origins of life is largely unknown, in part because little is known about its survivability and reactivity during impact with a planetary surface.

more at link.......

the paper:

https://pubs.rsc.org/en/content/articlelanding/2019/SC/C9SC00155G#!divAbstract

Synthesis of functionalized nitrogen-containing polycyclic aromatic hydrocarbons and other prebiotic compounds in impacting glycine solutions:

Abstract:

Proteinogenic amino acids can be produced on or delivered to a planet via impacting abiotic sources and consequently were likely present before the emergence of life on Earth. However, the role that these materials played in prebiotic scenarios remains an open question, in part because little is known about the survivability and reactivity of astrophysical organic compounds upon impact with a planetary surface. To this end, we use a force-matched semi-empirical quantum simulation method to study impacts of aqueous proteinogenic amino acids at conditions reaching 48 GPa and 3000 K. Here, we probe a relatively unstudied mechanism for prebiotic synthesis where sudden heating and pressurization causes condensation of complex carbon-rich structures from mixtures of glycine, the simplest protein-forming amino acid. These carbon-containing clusters are stable on short timescales and undergo a fundamental structural transition upon expansion and cooling from predominantly sp3-bonded tetrahedral-like moieties to those that are more sp2-bonded and planar. The recovered sp2-bonded structures include large nitrogen containing polycyclic aromatic hydrocarbons (NPAHs) with a number of different functional groups and embedded bonded regions akin to oligo-peptides. A number of small organic molecules with prebiotic relevance are also predicted to form. This work presents an alternate route to gas-phase synthesis for the formation of NPAHs of high complexity and highlights the significance of both the thermodynamic path and local chemical self-assembly in forming prebiotic species during shock synthesis. Our results help determine the role of comets and other celestial bodies in both the delivery and synthesis of potentially significant life building compounds on early Earth.

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I always find it fascinating that people consider the possibility of panspermia when exactly the same chemical components were available on Earth combined with an environment much more conducive of a complex chemistry.

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4 hours ago, pavelcherepan said:

I always find it fascinating that people consider the possibility of panspermia when exactly the same chemical components were available on Earth combined with an environment much more conducive of a complex chemistry.

It has also been shown that microscopic life forms can survive the effects of space and of course the same methodology is thought to be instrumental in delivering at least some of Earth's abundant water.

It is though just a hypothetical at this time, but certainly we know that at one time there was no life [universally speaking] then there was. 

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

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15 hours ago, beecee said:

It is though just a hypothetical at this time, but certainly we know that at one time there was no life [universally speaking] then there was. 

The reason I can't accept Panspermia is rather simple application of Occam's razor. If life has developed from 'non-life' somewhere, why would we assume it happened somewhere other than the Earth which (in our Solar system) has and always had the best conditions for life developing? I'm not saying it's impossible, but we would have to accept a) life forming first in a less hospitable environment, say Mars; then the life would have b) to survive some asteroid impact that would kick bits of the rock that it lives on into space; then c) the rock would be so lucky as to hit the Earth, then d) life would have to have survived the journey and e) life has to have survived the re-entry into Earth's atmosphere.

How likely does this set of coincidences look compared to life simply forming on Earth?

Edited by pavelcherepan

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19 minutes ago, pavelcherepan said:

The reason I can't accept Panspermia is rather simple application of Occam's razor. If life has developed from 'non-life' somewhere, why would we assume it happened somewhere other than the Earth which (in our Solar system) has and always had the best conditions for life developing?

Considering that Abiogenesis is really the only scientific answer to life arising from non life, and considering that we have already detected and tabled an interstellar interloper in our solar system, Panspermia is still a viable option.

Quote

 

I'm not saying it's impossible, but we would have to accept a) life forming first in a less hospitable environment, say Mars; then the life would have b) to survive some asteroid impact that would kick bits of the rock that it lives on into space; then c) the rock would be so lucky as to hit the Earth, then d) life would have to have survived the journey and e) life has to have survived the re-entry into Earth's atmosphere.

How likely does this set of coincidences look compared to life simply forming on Earth?

 

We are actually unaware of how many suitable [Earth like environments] that do exist elsewhere, but we do know that the stuff necessary for life [as opposed to the conditions] is everywhere, but certainly you are correct that Earth based life first evolved on Earth, and is still the most likely scenario. Note though, that all we are speaking of is "life, as we know it" and of course the many harsh conditions that basic microbial life can exist in. 

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1 hour ago, pavelcherepan said:

If life has developed from 'non-life' somewhere, why would we assume it happened somewhere other than the Earth which (in our Solar system) has and always had the best conditions for life developing?

That seems a pretty bold statement. Do you have a citation?

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28 minutes ago, zapatos said:

That seems a pretty bold statement. Do you have a citation?

Don't have a citation. Just a generalisation. I agree it's possible that for a short periods there could've been other places where conditions have been just as good. Should paraphrase it to: For majority of history Earth has had the best conditions for life developing.

Mars could have had decent atmosphere and liquid water but those ended very early on, water was almost completely gone by 3.5 bya. Venus also could have had conditions to support life, but then very early into the history underwent a runaway greenhouse effect and since then has most certainly been completely lifeless. Moons of giant planets have liquid water oceans, but depending on the size of the moon, there can be too little of valuable nutrients coming into the water which limits the chances of favourable chemical reactions. Also the low temperature slows down reactions.

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17 hours ago, beecee said:

It is though just a hypothetical at this time, but certainly we know that at one time there was no life [universally speaking] then there was. 

to quote zapatos :

52 minutes ago, zapatos said:

That seems a pretty bold statement. Do you have a citation?

 

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28 minutes ago, et pet said:

to quote zapatos :

 

The facts are that the most presentable model of the evolution of the universe is the BB. That did not include life only matter...you know, the elements and such.....For life to have evolved from a universe empty of life, means life evolving from non living matter. We call that Abiogenesis, and while we certainly do  not know the exact path of that process, Abiogenesis is the only scientific answer for life, universally speaking.

So the statement "certainly we know that at one time there was no life [universally speaking] then there was" is valid. 

41 minutes ago, pavelcherepan said:

Don't have a citation. Just a generalisation. I agree it's possible that for a short periods there could've been other places where conditions have been just as good. Should paraphrase it to: For majority of history Earth has had the best conditions for life developing.

Mars could have had decent atmosphere and liquid water but those ended very early on, water was almost completely gone by 3.5 bya. Venus also could have had conditions to support life,

Or possibly any number of the probable billions and billions of other planets in the galaxy/universe.

Edited by beecee

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7 minutes ago, beecee said:

Or possibly any number of the probable billions and billions of other planets in the galaxy/universe.

Here you run into both the Occam's razor and Fermi paradox. It's both extremely unlikely for the life to have been brought to us from outside the solar system and also there's no indication that complex life has in fact evolved in one of those billions and billions of other planets. Until we know for certain that abiogenesis was impossible on Earth, we should really stick to the idea that life did in fact form here.

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38 minutes ago, et pet said:

to quote zapatos :

This may help you also et pet. https://en.wikipedia.org/wiki/Abiogenesis

Abiogenesis, or informally the origin of life,[3][4][5][a] is the natural process by which lifehas arisen from non-living matter, such as simple organic compounds.[6][4][7][8] While the details of this process are still unknown, the prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but a gradual process of increasing complexity that involved molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes.[9][10][11] Although the occurrence of abiogenesis is uncontroversial among scientists, there is no single, generally accepted model for the origin of life, and this article presents several principles and hypotheses for how abiogenesis could have occurred.

more at link.....

<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>

 

Note carefully et pet, that the article starts of thus.......

"Origin of life" redirects here. For non-scientific views on the origins of life, see Creation myth.

Not to be confused with Biogenesis".

 

 

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15 minutes ago, beecee said:

So the statement "certainly we know that at one time there was no life [universally speaking] then there was" is valid. 

 

1 hour ago, zapatos said:

That seems a pretty bold statement. Do you have a citation?

 

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2 minutes ago, pavelcherepan said:

Here you run into both the Occam's razor and Fermi paradox. It's both extremely unlikely for the life to have been brought to us from outside the solar system and also there's no indication that complex life has in fact evolved in one of those billions and billions of other planets. Until we know for certain that abiogenesis was impossible on Earth, we should really stick to the idea that life did in fact form here.

I reject the Fermi paradox for obvious reasons....While we certainly have no evidence for any life off this Earth as yet, the sheer weight of numbers, and the extent of the universe, along with the stuff of life being everywhere we look, has the vast majority of scientists and cosmologists, certainly of the belief that it should exist. In fact if on the off chance we were alone, it would prompt far many more questions I suggest.

3 minutes ago, et pet said:

 

That seems a pretty bold statement. Do you have a citation?

That was not directed at me, and your question has been logically answered despite you failing to see that.

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16 minutes ago, beecee said:

Note carefully et pet, that the article starts of thus.......

"Origin of life" redirects here. For non-scientific views on the origins of life, see Creation myth.

Not to be confused with Biogenesis".

Note carefully, beecee, this is the Science News section. This is not the place to raise your "Creation myth".

 

Edited by et pet

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2 minutes ago, et pet said:

Note carefully, beecee, this is the Science News section. This is not the place to raise your "Creation myth".

Perhaps you need to read the relevant posts again, and cease your obvious nonsense....

again "Considering that Abiogenesis is really the only scientific answer to life arising from non life, and considering that we have already detected and tabled an interstellar interloper in our solar system, Panspermia is still a viable option"

 

and the link....

 

This may help you also et pet. https://en.wikipedia.org/wiki/Abiogenesis

Abiogenesis, or informally the origin of life,[3][4][5][a] is the natural process by which lifehas arisen from non-living matter, such as simple organic compounds.[6][4][7][8] While the details of this process are still unknown, the prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but a gradual process of increasing complexity that involved molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes.[9][10][11] Although the occurrence of abiogenesis is uncontroversial among scientists, there is no single, generally accepted model for the origin of life, and this article presents several principles and hypotheses for how abiogenesis could have occurred.

more at link.....

<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>

 

Note carefully et pet, that the article starts of thus.......

"Origin of life" redirects here. For non-scientific views on the origins of life, see Creation myth.

Not to be confused with Biogenesis".

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

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Note carefully, beecee, that you have yet to provide a citation for your petty bold statement

1 hour ago, et pet said:

certainly we know that at one time there was no life [universally speaking] then there was. 

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5 minutes ago, et pet said:

Note carefully, beecee, that you have yet to provide a citation for your petty bold statement

..A link was given, twice. All information with regards to Abiogenesis, the only scientific answer for the emergence of life, is there.

 

Edited by beecee

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48 minutes ago, beecee said:

I reject the Fermi paradox for obvious reasons....While we certainly have no evidence for any life off this Earth as yet, the sheer weight of numbers, and the extent of the universe, along with the stuff of life being everywhere we look, has the vast majority of scientists and cosmologists, certainly of the belief that it should exist. In fact if on the off chance we were alone, it would prompt far many more questions I suggest.

Sure, but also due to a sheer weigh of numbers, it's highly unlikely to have the first life brought to Earth even from one of the planets of Solar System. There's been quite a few meteorites from Mars found on Earth, most of those came during Late Heavy Bombardment. Those that have been studied so far, haven't shown any sign of life.

It's even far less likely that an asteroid from another star system in our galaxy managed to land on the Earth. The odds of that happening are so extremely small that it's not sensible to even consider them as an option while you have an entire planet capable of developing life. 

And I agree, there's likely life elsewhere in the universe, and Fermi did think so too, hence it's a 'paradox'. 

 

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5 minutes ago, pavelcherepan said:

Sure, but also due to a sheer weigh of numbers, it's highly unlikely to have the first life brought to Earth even from one of the planets of Solar System. There's been quite a few meteorites from Mars found on Earth, most of those came during Late Heavy Bombardment. Those that have been studied so far, haven't shown any sign of life.

It's even far less likely that an asteroid from another star system in our galaxy managed to land on the Earth. The odds of that happening are so extremely small that it's not sensible to even consider them as an option while you have an entire planet capable of developing life. 

And I agree, there's likely life elsewhere in the universe, and Fermi did think so too, hence it's a 'paradox'. 

 

We seem to agree on most aspects except perhaps the likelyhood of Panspermia.

I concur that Earth based Abiogenesis is certainly more certain then Panspermia, if as is probably most likely, Abiogenesis occurred elsewhere. But again, basic microbial life has been shown to be able to survive very harsh conditions. 

 

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7 hours ago, et pet said:

to quote zapatos :

 

It is not a bold claim at all. It is pretty obvious that life could not have existed in the early universe (if there were no atoms and therefore no molecules, there could be no life; unless you have a very odd definition for "life").

 

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7 hours ago, et pet said:

Note carefully, beecee, this is the Science News section. This is not the place to raise your "Creation myth".

 

This thread is about abiogenesis. Beecee provided a link to a page about the scientific study of abiogenesis (which starts out by pointing out that it is not about creation myths).

!

Moderator Note

Drop this line of discussion NOW.

 

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11 hours ago, et pet said:

Note carefully, beecee, that you have yet to provide a citation for your petty bold statement

!

Moderator Note

Oh, FFS, really? There was no life immediately after the BB, nor was it possible until after it was cool enough for atoms to form, and this should be pretty obvious to anyone. Which makes such a demand for a citation pretty obvious trolling. Knock it off. 

 

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Some more stuff on Abiogenesis and why it is the only scientifically viable answer to how life came to be........and obviously from someone who does know what they are talking about....

http://www.rationalskepticism.org/chemistry/calilasseia-78-papers-on-abiogenesis-t845.html

"Blind faith" in chemical evolution? Guess who hasn't read the scientific literature!

"Here's 78 scientific papers from the abiogenesis literature, that demonstrate conclusively that "blind faith" doesn't apply. Instead, what applies is direct experimental confirmation that the postulated chemical reactions WORK, and work under the prebiotic conditions postulated to have been present on the early Earth" ...

One of those papers is entitled....."A Combined Experimental And Theoretical Study On The Formation Of The Amino Acid Glycine And Its Isomer In Extraterrestrial Ices by Philip D. Holtom, Chris J. Bennett, Yoshihiro Osamura, Nigel J Mason and Ralf. I Kaiser, The Asatrophysical Journal, 626: 940-952 (20th June 2005)"

LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL

Here is a nice little illustration 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3718341/figure/RSOB120190f1/

An external file that holds a picture, illustration, etc. Object name is rsob-3-120190-g1.jpg

LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL

The above, at least to me, shows how two seemingly distinct processes of abiogenesis and evolution can be combined and addressed together and as a logical sequence.

It also illustrates the validity of my statement earlier on in this thread, that indeed at one time there was no life, then there was. 

 

Edited by beecee

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1 hour ago, beecee said:

The above, at least to me, shows how two seemingly distinct processes of abiogenesis and evolution can be combined and addressed together and as a logical sequence.

Just to be a devil's advocate, I'd say that even without any kind of blind faith in creation myths or religion that you mentioned in the other (now closed thread), there can be plenty of valid reasons to question abiogenesis. Personally, I surely don't, but let's face the facts. Apart from a few experiments where simple simulations of conditions in primordial oceans have been done and resulted in some rather complex molecules being formed as the end product, there are no real facts or models of how exactly simple chemistry could've lead to forming of something as complex as DNA or RNA.

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2 minutes ago, pavelcherepan said:

 there are no real facts or models of how exactly simple chemistry could've lead to forming of something as complex as DNA or RNA.

Yes, I already alluded to that. Still the fact that at one time the universe had no life, then there was life, can only be explained scientifically by Abiogenesis.

 

19 hours ago, beecee said:

 While the details of this process are still unknown, 

 

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