[larens (OP)]

The Rare Earth hypothesis should be the default position to explore given the Fermi Paradox and the fact that we have not found any signs of life elsewhere in the universe. We should thus form an inverse Drake equation, and look for a set of highly improbable facts about the Solar system. Given the difficulty of life originating in an environment thermodynamically far downhill from the conditions in cells, we should be looking for an early environment with highly energetic molecules and kinetics that leads to the biochemistry we see. This requires a highly improbable event, i.e., an intense gamma ray burst from a neutron star merger.

The second improbable fact is that the Solar system is on the boundary of chaos, because of the asteroids Ceres and Vesta. From geology Ceres appears to have come from the outer Solar system and Vesta from the inner. Their orbits nearly intersect so they can have captured each other into their current positions in the main asteroid belt. The moons of Mars are strong evidence for this capture process. One is retreating from Mars synchronous orbit and the other descending.  Their spectra correspond to a mixture of ejecta from Mars and material with a high organic content. This is indicative of Vesta having had a satellite with organic material that was disrupted in a close encounter with Mars. This encounter would have been necessary to project Vesta into its current position. Vesta presumably was originally in a resonance with Earth that allowed it to reside for a long enough time in a temperature zone conducive to the origin of life. The unusually large crater on Vesta may have been caused by a collision with a piece of its former satellite. A band of hydrated clay on Vesta is incompatible with its otherwise igneous surface. Because Vesta has a short rotation period, a tidally locked satellite would have readily formed a ring. Besides leading to the band of clay this ring would have been important in the harvesting of chemicals for life on the satellite.

The third improbable fact is that  just before the Solar system started a supernova created radioactive isotopes that heated asteroids to the point of creating liquid water in them that allowed the processing of the chemicals necessary for life.

The final improbable fact is that the Solar system is very regular, so life once created is not destroyed by asteroidal impacts.

This lays out the basic evidence for this scenario. I will go into the specific biochemistry in future replies. For the moment please address the basic scenario. Virgins to posting are particularly welcome. This forum has had too many lurkers to make for good discussion.

[Kryptid]

Vesta presumably was originally in a resonance with Earth that allowed it to reside for a long enough time in a temperature zone conducive to the origin of life.

Merely being at Earth's orbit is insufficient in itself to create the temperatures needed for life. Any satellite of Vesta must have been very small and thus incapable of holding any substantial atmosphere. In this respect, it would be expected to experience temperature swings like that of the Moon (which is also at the Earth's orbit). This combination of a lack of surface pressure and temperature extremes from 100 kelvins to 390 kelvins would preclude the existence of liquid water on its surface and thus it would be a poor candidate for the development of life.

[larens (OP)]

This combination of a lack of surface pressure and temperature extremes from 100 kelvins to 390 kelvins would preclude the existence of liquid water on its surface and thus it would be a poor candidate for the development of life.

I said that the location was in a "warm spring". This would mostly be at the average temperature or higher. Extremes in temperature are necessary to drive the purification of solvents, reagents, and biochemicals, e.g., by the fractional freezing of aqueous solutions. Formamide is an important secondary solvent. It is more polar than water and freezes at about the same temperature. Swings to a much lower temperature are necessary to generate a slowly alternating electric potential to purify by electrophoresis. The ferroelectric transition temperature of ammonium sulfate is 224 Kelvin. There would be organic materials available to seal against the vacuum.

[Kryptid]

I said that the location was in a "warm spring".

You might as well posit that warm spring as being on Earth then, rather than on some object that we don't know even existed.

Extremes in temperature are necessary to drive the purification of solvents, reagents, and biochemicals, e.g., by the fractional freezing of aqueous solutions. Formamide is an important secondary solvent. It is more polar than water and freezes at about the same temperature. Swings to a much lower temperature are necessary to generate a slowly alternating electric potential to purify by electrophoresis.

We don't know the conditions necessary for the formation of life. As such, we don't know if these processes you speak of are needed. Alternatively, freezing and thawing can easily occur in some locations on Earth when the seasons change.

[larens (OP)]

You might as well posit that warm spring as being on Earth then, rather than on some object that we don't know even existed.

The Earth is a hostile environment for the formation of life, because of the abundance of water. Without a sophisticated cellular membrane biochemicals are rapidly diluted. The necessary high energy molecules are also rapidly destroyed.

We don't know the conditions necessary for the formation of life.

We know a lot about these conditions. Unless we resort to vitalism, they have to lead to the formation of life by mostly known physics, chemistry, and biology.

[Kryptid]

The Earth is a hostile environment for the formation of life, because of the abundance of water. Without a sophisticated cellular membrane biochemicals are rapidly diluted. The necessary high energy molecules are also rapidly destroyed.

So what's the difference between a warm spring on a hypothetical satellite of Vesta and a warm spring on Earth? Moreover, why assume that it was on a satellite of Vesta? Why not on one of the other countless asteroids in the asteroid belt?

Unless we resort to vitalism, they have to lead to the formation of life by mostly known physics, chemistry, and biology.

And you think those conditions would necessarily be unique to a heavenly body that we don't even know existed?

[larens (OP)]

So what's the difference between a warm spring on a hypothetical satellite of Vesta and a warm spring on Earth? Moreover, why assume that it was on a satellite of Vesta? Why not on one of the other countless asteroids in the asteroid belt?

The difference is between being in a friendly environment and being in a hostile environment.

No other body in the Solar system is supported by as much evidence as I gave for the hypothetical satellite of Vesta. This subsidiary hypothesis is mandated by needing a simple and consistent solution for the larger hypothesis that life originated by natural processes.

[Kryptid]

The difference is between being in a friendly environment and being in a hostile environment.

What makes a warm spring on that satellite more friendly to life than a warm spring on Earth?

No other body in the Solar system is supported by as much evidence as I gave for the hypothetical satellite of Vesta.

Seriously? You think there we have more evidence for the existence of Vesta's satellite than we have for Earth, the Sun, Mars, etc?

[larens (OP)]

What makes a warm spring on that satellite more friendly to life than a warm spring on Earth?

The context was friendly for the origin of life - for the reasons I gave.

Seriously? You think there we have more evidence for the existence of Vesta's satellite than we have for Earth, the Sun, Mars, etc?

The context was existence as a location for the origin of life - also for the reasons I gave.

[Kryptid]

The context was friendly for the origin of life - for the reasons I gave.

Those same conditions can exist in springs on Earth.

The context was existence as a location for the origin of life - also for the reasons I gave.

Which goes back to what I was saying about any number of other asteroids being just as good a candidate.

[larens (OP)]

Those same conditions can exist in springs on Earth.
…

Which goes back to what I was saying about any number of other asteroids being just as good a candidate.

Instead of just repeating yourself, go back to my OP and reply #2 to see the conditions I laid out.

[Kryptid]

Instead of just repeating yourself, go back to my OP and reply #2 to see the conditions I laid out.

You don't know that those conditions you specified are capable of producing life, nor do you know that alternative conditions can't also produce life. Regardless, formamide and ammonium sulfate could have existed on the prebiotic Earth as well. There are locations on the Earth even today where the ferroelectric temperature you speak of can be reached. So again, your arguments do not preclude life from forming on Earth.

[larens (OP)]

You don't know that those conditions you specified are capable of producing life, nor do you know that alternative conditions can't also produce life. Regardless, formamide and ammonium sulfate could have existed on the prebiotic Earth as well. There are locations on the Earth even today where the ferroelectric temperature you speak of can be reached. So again, your arguments do not preclude life from forming on Earth.

The first phrase in my OP says that I am presenting an hypothesis. I am not precluding life forming on the Earth. I am also not going to hold my breathe until someone produces a coherent theory about the origin of life on the prebiotic Earth using the substances you mentioned.

[Kryptid]

The first phrase in my OP says that I am presenting an hypothesis.

Fair enough.

I'm more confused as to why you are trying to point to one particular object in the asteroid belt (and one that we don't know ever existed at that). Why would it be so uniquely suited for the development of life when compared to other asteroids?

[larens (OP)]

I'm more confused as to why you are trying to point to one particular object in the asteroid belt (and one that we don't know ever existed at that). Why would it be so uniquely suited for the development of life when compared to other asteroids?

There is only one important reason one cannot get from my OP and reply #2. I did not mention that my hypothesis includes the idea that the warm spring was on the face of the satellite directly facing Vesta. The large frequent eclipses of the Sun were good for driving the temperature fluctuations necessary to the system. The satellite was near the Roche limit. As I mentioned the resulting ring allows for good interaction with the larger environment. Vesta is the second most massive asteroid and would have been a good source of sulfur dioxide.

[larens (OP)]

Vesta is the second most massive asteroid and would have been a good source of sulfur dioxide.

Vesta was large enough to melt and outgas sulfur dioxide. This was important to form large amounts of ferroelectric ammonium sulfate to create electric potentials that can form the polypeptides that we see in biology. These are generally on the boundary between conduction and nonconduction. They can thus act as field effect transistors and guide other reactions.

Hydrogen cyanide (HCN) and formaldehyde (CH2O) are the two most important molecules formed by radiation energetic enough to split diatomic molecules. They are abundant in the nebula around very hot stars and would be created in much higher concentrations by the intense radiation from a neutron star merger. HCN combines with water to form formamide ((NH2)CHO). It can also combine with itself to form the bases for RNA and DNA, e.g., adenine (C5H5N5). Formaldehyde readily and reversibly polymerizes to polyoxymethylene. With borate as a catalyst the reaction forms ribose (C5H10O5) for  RNA and DNA. This proceeds particularly well with formamide as the solvent. The reaction of nickel phosphide (abundant in iron/nickel meteorites) with water yields activated phosphates for ATP (and RNA, and DNA).

[puppypower]

In the Miller-Urey Experiments of the 1950's they used an electric arc to create the high energy molecular states needed to form amino acids and many other compounds, from the simple gases that were assumed to be present on the early earth. The compounds that formed included very complex hydrocarbons that one would swear came from fossil fuel deposits. It is possible much of the fossil fuel we assume came from life, came before life, but was infiltrated later by life. Miller was able to form complex tars suitable for coal formation. 

When you have a lot of water; oceans, and a hot summer day, you can get hurricanes and thunderstorms which produce lightning within the gases of the atmosphere. The Miller experiments were simulating lighting in gases, and made many of the precursors needed for life.

The Miller experiment and variations thereof, could start with a reduced or oxidized atmosphere and still make amino acids, as long as water molecules were part of the reaction. Water makes lighting to create activation energy, so other water molecules can combine, with various combinations of gases; ammonia NH3 to nitrogen N2 to form the precursors of life. Water is the swiss army knife of chemistry.

Going from amino acids to protein is more complicated, since the polymerization of amino acids into protein will give off water molecules. If the amino acids are initially dissolved in water, the bulk water will inhibit the formation of protein, since the surplus of water makes it harder for the amino acids to kick off water and polymerize.

Experiments, that did successfully make protein, used the opposite or dehydration of amino acids in clay. This suggests life beginning between land and sea; thunderstorms, dehydration at low tide, and tidal mixing at high tide. Water has many jobs.

The way water helps with assembly of smaller organic things into even larger precursors is connected to the water-oil affect. If we mix water and oil, and let it settle, the water and oil will separate into two phases. Water and oil can spontaneously go from disorder to order. The mixing of water and organics creates surface tension; tides. The phase separation lowers this tension; lowers potential. As complex organics appear in water, and the tides mix the water and organics, water and organics will phase separate out at low tide, into order; simple organelles.

As a home experiment mix spices, water and olive oil, shake and allow to settle. All the organic flavor will end up in the oil, which will separate from the water. The water-oil affect is one of the better tools in the swiss army knife called water.

[Bored chemist]

They are abundant in the nebula around very hot stars and would be created in much higher concentrations by the intense radiation from a neutron star merger.

Actually, they would be destroyed in those conditions.

[larens (OP)]

As complex organics appear in water, and the tides mix the water and organics, water and organics will phase separate out at low tide, into order; simple organelles.

Organelles are greatly more complex than simple mixtures of phases. Vigorously mixing things with water is a good way of rapidly increasing entropy. In general the processes you mention create gunk. On Earth there were not effective enough ways, e.g., electrophoresis to separate mixtures of chemicals into relatively pure components that can serve as building blocks for life.

Actually, they would be destroyed in those conditions.

Diatomic molecules in the initial Solar nebula are destroyed. Significant amounts of HCN and CH2O are formed when the atoms recombine.

[larens (OP)]

Formaldehyde readily and reversibly polymerizes to polyoxymethylene

Polyoxymethylene chains joined with halloysite clay crystals to form the initial shaft and chain system that drove mechanochemistry in the initial form of life. Halloysite clay crystals are small hollow scrolls, which can serve as shafts and tubes. They grow by elongation, which when combined with fracturing into definite lengths can serve to replicate patterns.  Today cells depend on rotary motors driven by pH differences, These are the structural fossils of the initial system. The initial pH differences were between warm springs and their surrounding environment.

The cofactors of enzymes are chemical fossils that indicate the essential minerals in the initial system. We may infer that chalcopyrite (CuFeS2) was the initial catalyst and molybdenum disulfide served as shelving for storage. It crystalizes as 2-D layers that may easily be intercalated. Quartz crystals probably served as windows for primitive photosynthesis. The isotope ratios of graphite inclusions in zircons from very old rocks on Earth show that photosynthesis had been transferred to Earth by at least 4.1 billion years ago.