Abiogenesis and life on Earth - thoughts and pet theories?

[Asbo Zaprudder]

The OSIRIS-REx samples returned from the asteroid Bennu have been analysed and found to provide support for the pseudo-panspermia hypothesis. The Samples contained all five nucleobases used by life on Earth as well as 14 of the 20 amino acids - although both left and right-handed forms were present. The amino acids present in life on Earth are left-handed, apart from glycine, which is achiral. However, I wonder if the investigation has eliminated the possibility that Bennu itself was formed by a collision with a very young Earth, given that Bennu is an Apollo group asteroid.

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[Will The Serious]

Studies of rock and dust from asteroid Bennu delivered to Earth by the OSIRIS-REx spacecraft have revealed molecules that, on our planet, are key to life, as well as a history of saltwater that could have served as the “broth” for these compounds to interact and combine.
https://science.nasa.gov/mission/osiris-rex/

The saltwater would suggest your thoughts of a collision with Earth or an ejection from Earth due to a collision, is a strong possibility.

Scientists hope the Bennu sample will reveal whether asteroids that collided with Earth billions of years ago thereby delivered water and other ingredients for life to our planet.

or from our planet. Will carbon dating or some other more accurate test, reveal how old the samples are? If they came from Earth, they won't be any older than Earth's earliest life. If they came from some other source, such as an outside source that could have seeded Earth's life, they may be much older than Earth itself.

Personally, I find the idea that these samples traveled any distance before reaching our solar system, highly unlikely. To have come from another star system would have taken a great deal of time at a time when there wasn't that much time for life to have had the time to develop it's building blocks elsewhere, and experience a catastrophic event that sent samples of it hurtling off into space to eventually find a cool enough Earth to build upon.

On the other hand, if enough of these building blocks dispersed into space that a single sample or more found Earth, they would likely have found many more bodies to land on. Mars and Saturn's moons included. Mimas wobbles in an unusual way, so maybe a collision with a large, life's building blocks carrying asteroid. Lapetus has a unique orbit that could indicate its origins are from outside our solar system. Maybe it is the extra-solar source of life in our system.

-Will

 

[Kamen Rider Blade]

The OSIRIS-REx samples returned from the asteroid Bennu have been analysed and found to provide support for the pseudo-panspermia hypothesis. The Samples contained all five nucleobases used by life on Earth as well as 14 of the 20 amino acids - although both left and right-handed forms were present. The amino acids present in life on Earth are left-handed, apart from glycine, which is achiral. However, I wonder if the investigation has eliminated the possibility that Bennu itself was formed by a collision with a very young Earth, given that Bennu is an Apollo group asteroid.

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That's cool, I wonder how many other planets within our Universe have had Sentient life evolved on it over millions to billions of years if PanSpermia turns out to be true.

 

[Asbo Zaprudder]

That's cool, I wonder how many other planets within our Universe have had Sentient life evolved on it over millions to billions of years if PanSpermia turns out to be true.

There was a recent study that indicated sufficient H, C, N, O, P, S, Fe and other elements would have been around a few hundred million years after the Big Bang - any elements above H, He and Li in the periodic table needing to be produced by nucleosynthesis in massive stars and scattered when those stars went supernova. I assume after billions of years that the probability rose higher. Interesting that minerals in the Murchison meteorite predate the solar system by 2.5 billion years.

 

[Kamen Rider Blade]

There was a recent study that indicated sufficient H, C, N, O, P, S, Fe and other elements would have been around a few hundred million years after the Big Bang - any elements above H, He and Li in the periodic table needing to be produced by nucleosynthesis in massive stars and scattered when those stars went supernova. I assume after billions of years that the probability rose higher. Interesting that minerals in the Murchison meteorite predate the solar system by 2.5 billion years.

So given that the current Estimate that our Universe is 13.8B y/o w/ a ± factor of 4.0B.

I wonder how many other M-Class Planets might have already gone through similar evolution cycles as we have.

 

[Asbo Zaprudder]

So given that the current Estimate that our Universe is 13.8B y/o w/ a ± factor of 4.0B.

I wonder how many other M-Class Planets might have already gone through similar evolution cycles as we have.

As far as I'm aware M-class planet is a Star Trek term, but potentially the number of earth-like planets is the same order as the number of stars which have life spans of more than 10^10 years, so more than 10^21 in the visible universe if we assume 10% of such stars have such planets; 10^10 in our galaxy. However, given current detection methods, we currently don't have a good estimate of the ratio of earth-like planets to G, K and M-type stars. The number suitable for bearing life and remaining so for long enough might be a much lower fraction.

 

[Kamen Rider Blade]

As far as I'm aware M-class planet is a Star Trek term

I know, but we're on a "Star Trek" focused BBS/Forum.
So the terminology fits with the fanbase.

 

[Asbo Zaprudder]

I know, but we're on a "Star Trek" focused BBS/Forum.
So the terminology fits with the fanbase.

There is a separate forum for Trek Tech. I have no idea what the definition of an M-class planet is other than it's what the plot of the week demands. We might as well discuss the rules of Fizzbin.

 

[Kamen Rider Blade]

There is a separate forum for Trek Tech. I have no idea what the definition of an M-class planet is other than it's what the plot of the week demands. We might as well discuss the rules of Fizzbin.

Class M Planets are planets suitable for Humanoids like us.

 

[Asbo Zaprudder]

Class M Planets are planets suitable for Humanoids like us.

That's still a rather unscientific definition, but it's basically what I assumed. Even with the thousands of extrasolar planets discovered, only a very small number seem to be even remotely potentially habitable by humans. That's partly due to detection techniques, but what if it turned out that the Earth is a statistically very unlikely outlier? It might solve the Fermi Paradox. That we're unique is one of AC Clarke's options for the ubiquity of life in the cosmos - that it isn't - but is that prospect really as terrifying as he stated? We just don't have enough data to sensibly feel existential dread.

 

[Will The Serious]

That's partly due to detection techniques, but what if it turned out that the Earth is a statistically very unlikely outlier? It might solve the Fermi Paradox.

Consider the number of stars in our galaxy that make up the galactic "habitable zone."

Estimates suggest that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way. -Google AI summery-

The galactic habitable zone
Even if a true sister Earth orbiting an M class star at the right distance, tilt, and ellipsis counted only 0.001% of those estimated "habitable" planets, that's still 4 million possible planets with life developing exactly the way it is believed to have done on Earth. Then there is the number of galaxies with similar galactic habitable zones, and we are looking at trillions of possible mirror Earth-like evolutions.

If we consider the possibility that interstellar and even intergalactic travel for humans may actually become practical at some point in our technological evolution, how much further ahead of us would an intelligent alien species have to be to have, not only made it out into the habitable zone neighborhood, but then to find our single planet and decide to come visit us, by now?

I believe studies have suggested that our sun isn't that much younger than our galaxy and that Earth, by cosmic standards, isn't that much younger than the sun. The first true life forms to appear on Earth happened almost immediately after Earth cooled enough to support life.

We may indeed be an outlier for early development of life, but what are the chances that we are in the earliest 0.1%? Even a headstart of a million years could put an alien extraterrestrial race significantly ahead of us technologically. There may be 4 billion planets with cave dwelling primates on them, and only a million with intelligence and technology more advanced than the Iron Age, but give an Iron Age culture a million year headstart and imagine where they may be compared to us?

In cosmic, even galactic time scales, a million extra years is like crossing the finish line by a 100th of a second lead. In terms of technological evolution, that's going from running fearfully from fire to colonizing the next planet over, and then some.

-Will

 

[Asbo Zaprudder]

Please don't confuse M-type stars with class M planets.

Stellar classification - Wikipedia

en.wikipedia.org

Class M planet - Wikipedia

en.wikipedia.org

Planets around many M-type stars might be uninhabitable because of the large number of flares that they generate. While such stars might last trillions of years compared to 8 to 70 billion years for the mass range of G and K-type stars, they might also sterilise any planets in their systems.

However, some astrophysicists think that planets might be spared if the flare activity is concentrated around the magnetic poles of the stars.

Why do red dwarf (M-type) stars give off such violent flares and CMEs, out of proportion to their size and temperature?

Dr. Becky (Smethurst) just posted a new YouTube video mentioning, as I have heard many times, that it might not be possible for life to form on planets around Red Dwarf (M) stars because they would...

astronomy.stackexchange.com

 

[Asbo Zaprudder]

This Wikipedia page contains some information on estimating how many human-habitable planets might exist in our galaxy, assuming the rare earth hypothesis.

Rare Earth hypothesis - Wikipedia

en.m.wikipedia.org

The observations currently seem to favour the rare earth hypothesis rather than the mediocrity principle. However, I haven't investigated whether any deeper statistical analysis has been performed to confirm this - say by running Monte Carlo analysis to determine what populations of possible planetary system configurations would reproduce the data measured so far and what would be predicted by new or extended measurement techniques.

The uncertainties are very large, so I wouldn't have much faith in any estimate. The same comment also applies to the Drake equation, of course. When I played around with that, I came up with an estimate of between 1 and 25 advanced civilisations in our galaxy. Whether we should consider ourselves as being one of them is another matter.

 

[Will The Serious]

Interesting. In thinking about the implications of how, when, and where life first formed, we must consider the environment in which it can form.
Water Might Have Formed Long Before Galaxies.

Of course, as the article points out, there would be no water without oxygen, so when did oxygen form? Some cosmic conditions that could form the elements besides Hydrogen and Helium had to have existed very soon after whatever event was the "first" event that formed the first two elements.

It is almost a certainty that the first water formation was a gaseous state, boiling off into outer-space as fast as light, but still, water molecules have much more mass than hydrogen or helium, so water may have been directly involved with the first star formations, and thus, galaxy forming. It could be that oxygen and water provided the pressure to force the formation of massive bodies that may then turn into stars that would go super-nova and form even more and heavier elements. Soon, the planets were born too. Life, at least the example of it that we have seen, needs water. But, it also needs carbon. So first, water, then... then life.

-Will

 

[Asbo Zaprudder]

As far as we know there was no oxygen before there were stars, which is what the linked article states. The nucleosynthesis conditions during the Big Bang didn't produce any significant amount of elements beyond helium and lithium. Oxygen is the third most common element so water is almost certainly ubiquitous. Water molecules might have more mass but their gravitational effect is still tiny. They do have an electric dipole moments though and electromagnetic forces might have been much more important in a more closely packed early universe than they are now where galaxies are separated by several million light years on average.

ETA: I'd have to read the original paper to give a more informed opinion, but it doesn't sound outlandish from what is reported in the article.

This is the abstract from that paper:

Primordial (or population III) supernovae were the first nucleosynthetic engines in the Universe, and they forged the heavy elements required for the later formation of planets and life. Water, in particular, is thought to be crucial to the cosmic origins of life as we understand it, and recent models have shown that water can form in low-metallicity gas like that present at high redshifts. Here we present numerical simulations that show that the first water in the Universe formed in population III core-collapse and pair-instability supernovae at redshifts z ≈ 20. The primary sites of water production in these remnants are dense molecular cloud cores, which in some cases were enriched with primordial water to mass fractions that were only a factor of a few below those in the Solar System today. These dense, dusty cores are also probable candidates for protoplanetary disk formation. Besides revealing that a primary ingredient for life was already in place in the Universe 100–200 Myr after the Big Bang, our simulations show that water was probably a key constituent of the first galaxies.

Abundant water from primordial supernovae at cosmic dawn - Nature Astronomy

State-of-the-art computer simulations show that the first water in the Universe formed in primordial supernova remnants 100 Myr after the Big Bang, enriching future sites of planet formation to levels that were nearly those in the Solar System today.

www.nature.com

 

[Asbo Zaprudder]

An interesting suggestion for how the Lenard effect (aka spray electrification or the waterfall effect) rather than lightning strikes could have provided the initial spark of life on Earth that bonded carbon to nitrogen in sufficient quantities - a requirement for creating amino acids and nucleotide bases:

Abstract:

When neutral water is sprayed, oppositely charged microdroplets are formed. The close approach of oppositely charged microdroplets causes an electrical discharge and leads to luminescent emission. The light emission happens without any external voltage applied, and the electrical discharge is sufficiently energetic to excite, dissociate, or ionize surrounding neutral gas molecules. Thus, sprayed water microdroplets cause chemical reactions to occur. Similar findings to the Urey-Miller experiment were observed by spraying room temperature water microdroplets into a gas mixture containing nitrogen, methane, carbon dioxide, and ammonia, which leads to the synthesis of organic molecules containing carbon-nitrogen (C─N) bonds. These observations provide another explanation for unique reactivity at the gas-water interface, as well as a possible mechanism for making the building blocks of life on early Earth.

Spraying of water microdroplets forms luminescence and causes chemical reactions in surrounding gas

https://www.science.org/doi/10.1126/sciadv.adt8979

The experiments produced compounds such as hydrogen cyanide (HCN), the amino acid glycine, and the pyrimidine nucleotide base uracil, one of the components of RNA. On the early Earth, sprays of oceanic water that landed on rocks could have created organic chemicals that concentrated in crevices. Subsequent drying and rewetting would then have polymerised short molecules into longer chains. One conclusion is that extra-terrestrial life on other planets or moons might be more likely to occur in locations that allow tiny droplets of water to form and collide.

 

[Will The Serious]

Are we thinking that life originally formed in freshwater? I am under the impression that life on Earth is of a saltwater base.

The experiments produced compounds such as hydrogen cyanide (HCN), the amino acid glycine, and the pyrimidine nucleotide base uracil...

Did any of these experiments produce NaCl and MgSO4? I'm guessing water and electricity are necessary but there's still more. Pressure, release from pressure, matrix organizing crystallization needs a slow cooling and/or release from pressure. I say crystallization because that is a natural organizing process that leads to the building of organized structures such as snowflakes and quartz and salt crystals. These organized structures contribute to natural building of electronic components like natural capacitors and radio wave inductors.

-Will

 

[Asbo Zaprudder]

Are we thinking that life originally formed in freshwater? I am under the impression that life on Earth is of a saltwater base.

Oceanic, but I agree a pH imbalance is possibly required. The scenario discussed is more warm little pond than hydrothermal vent, although volcanic rocks or clays could be involved.

Did any of these experiments produce NaCl and MgSO4?

No. What is being discussed is how to bond carbon and nitrogen into compounds from atmospheric gases and how to polymerise the simple compounds formed. Salts such as the ones you mention form without the presence of life.

I'm guessing water and electricity are necessary but there's still more. Pressure, release from pressure, matrix organizing crystallization needs a slow cooling and/or release from pressure. I say crystallization because that is a natural organizing process that leads to the building of organized structures such as snowflakes and quartz and salt crystals. These organized structures contribute to natural building of electronic components like natural capacitors and radio wave inductors.

Such crystals don't require life in order to form. The minerals in certain types of clay have long been recognised to have a potential catalysing action for assisting in polymerisation. There was even a suggestion that clays provided a sort of genetic memory prior to RNA or DNA, but that idea has fallen by the wayside.

 

[publiusr]

Between those and pulsars…we’re being punked’

 

[Snowdrop82]

I was never a big believer or convinced in the idea of life evolving independently on Earth. It probably came from elsewhere in the Solar System or beyond.