Tardigrades survive impacts of up to 825 meters per second:

[beecee]

https://phys.org/news/2021-05-tardigrades-survive-impacts-meters.htmlMAY 21, 2021 REPORT

the paper:

https://www.liebertpub.com/doi/10.1089/ast.2020.2405

Tardigrade Survival Limits in High-Speed Impacts—Implications for Panspermia and Collection of Samples from Plumes Emitted by Ice Worlds:

Abstract

The ability of tardigrades to survive impact shocks in the kilometer per second and gigapascal range was investigated. When rocks impact planetary surfaces, the impact speeds and shock pressures are in the kilometer per second and gigapascal range. This investigation tested whether tardigrades can survive in impacts typical of those that occur naturally in the Solar System. We found that they can survive impacts up to 0.9 km s−1, which is equivalent to 1.14 GPa shock pressure, but cannot survive impacts above this. This is significantly less than the static pressure limit and has implications for tardigrade survival in panspermia models. The potential survival of tardigrades in impacts of terrestrial impact ejecta on the Moon is shown to be impossible for the average lunar impact speed of such ejecta. However, a notable fraction (around 40%) of such ejecta impact at vertical speeds low enough to permit survival. Similarly, martian impact ejecta striking Phobos, for example, at a typical impact speed will not permit viable transfer of tardigrade-like organisms, but if a fraction of such material had a lower impact speed, survival may be possible. We also consider the implications of this for the collection of viable samples by spacecraft transiting the plumes of icy water worlds such as Europa and Enceladus. We have found the limit on survival of shocks to be around 1 GPa, which is instrumental in determining appropriate mission scenarios and collection methods for the acquisition of viable materials.

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While we can be certain that Universal Abiogenesis is the only scientific process by which life arose in the Universe, we are less certain as to whether that Abiogenesis was Earth based or via the process we call Panspermia.

Perhaps both played a part? Any thoughts?

[StringJunky]

It seems sensible to me to eliminate Earth-based abiogenesis first, since all the elements necessary for life exist here. Having said that, each planet or other body is possibly a dedringer for the same conditions in the long-distant past here on Earth and may help to tell the story of life's evolution.

Edited May 24, 2021 by StringJunky

[joigus]

I'm not sure that tardigrades and panspermia are the key that unlocks this mystery. Resilience and "latency" suggest to me as mechanisms to make life more secure and widespread once it's started out and got a secure grip. Abiogenesis, I think, must be the key. Abundant water, energetic processes, chemical pumps in the way of volcanoes, RNA/amino acids worlds, maybe crystals as scaffolds for building of macromolecules, physico-chemistry of lipid membranes... These's a reason why ideas like these are suggested over and over. Speaking from sheer intuition, I think variants of abiogenesis are the way to go, and panspermia is peripheral.

To me, panspermia is just pushing the problem somewhere else, but I'd be very interested to learn from other members' opinions.

[dimreepr]

Well, we're here too... 

A pandemic, is just another version of "the war of the world's".

Life will find a way.

Once started... Who knew when that happened... 

[beecee]

On 5/25/2021 at 7:02 AM, StringJunky said:

It seems sensible to me to eliminate Earth-based abiogenesis first, since all the elements necessary for life exist here. Having said that, each planet or other body is possibly a dedringer for the same conditions in the long-distant past here on Earth and may help to tell the story of life's evolution.

Agreed.

[beecee]

On 5/25/2021 at 10:32 PM, joigus said:

To me, panspermia is just pushing the problem somewhere else, but I'd be very interested to learn from other members' opinions.

The possibility of Earth based abiogenesis and Panspermia may have operated together? But yes, you do have a valid point..The pertinent question though is not "whether life came about and arose through chemical processes" that's a scientific given, but simply which pathway was followed to produce the first life, speaking universally. 

[joigus]

13 hours ago, beecee said:

The pertinent question though is not "whether life came about and arose through chemical processes" that's a scientific given, but simply which pathway was followed to produce the first life,

Yes, I'm aware of this. This is the reason behind "maybe" when I said "maybe crystals..."

I find this hypothesis --perhaps in combination with the RNA world idea-- very promising:

https://en.wikipedia.org/wiki/Robert_Hazen#Origins_of_life

This guy et al. did a re-run of the Miller-Urey experiment, but they added minerals, and found interesting results:

Quote

they tried subjecting pyruvate in water to high pressure, hoping for a simple reaction that would return oxaloacetate. Instead, an analysis by an organic geochemist, George Cody, found that they obtained tens of thousands of molecules.

Pyruvate and oxaloacetate are important intermediates in cellular respiration, so I guess they were trying to look for a primitive version of it in a convenient "chemical cauldron".

Documentary (Life's Rocky Start): https://www.youtube.com/watch?v=zA4w0b2WRvo

 

Things like tardigrades and other resilient organisms I tend to see as shedding light on amazing phenomena as: How is it possible that multicellular organisms endured episodes as Snowball Earth, and the like? Kind of like a second-order mechanism providing plausible explanation of life taking hold in spite of these cataclysmic episodes.

[beecee]

9 hours ago, joigus said:

Yes, I'm aware of this. This is the reason behind "maybe" when I said "maybe crystals..."

I'm well aware you are aware of it. 🙂My point was to convey the fact generally speaking, that while we are uncertain of the exact pathway, Abiogenesis is still the only scientific theory we have for the emergent of life. Sometimes that fact is lost or misinterpreted by some people.

And an excellent post, thanks.

[joigus]

19 hours ago, beecee said:

I'm well aware you are aware of it. 🙂My point was to convey the fact generally speaking, that while we are uncertain of the exact pathway, Abiogenesis is still the only scientific theory we have for the emergent of life. Sometimes that fact is lost or misinterpreted by some people.

And an excellent post, thanks.

There is very little I can recall you as not being aware of --if anything at all.  I just want this post to be as much (and as longer) alive as possible, because it interests me very much. In fact, it's inspired me to think of opening another, related, post. I'm working on it.

[StringJunky]

I wonder if they did them in the dessicated state as well as hydrated state? Maybe they can survive greater extremes in the dessicated state.

[beecee]

3 hours ago, joigus said:

There is very little I can recall you as not being aware of --if anything at all.  I just want this post to be as much (and as longer) alive as possible, because it interests me very much. In fact, it's inspired me to think of opening another, related, post. I'm working on it.

I'm looking forward to it. On my awareness, gee thanks! Let me do some thinking on that though.😉

Edited May 28, 2021 by beecee

[CharonY]

On 5/27/2021 at 6:36 AM, joigus said:

Pyruvate and oxaloacetate are important intermediates in cellular respiration, so I guess they were trying to look for a primitive version of it in a convenient "chemical cauldron"

So there is a view that metabolites of the acetyl coA pathway are ancient. However, there is also the discovery that certain alloys can convert hydrogen and carbon dioxide into formate, acetate and pyruvate. I.e. they can be formed without enzymatic activities which would in theory allow organisms to utilize them, without having any producers first.

(Preiner et al. 2020; https://doi.org/10.3390/life8040041)