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Could life thrive on hydrogen-rich alien worlds?

Mar 19, 2020
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Quoting from the article:

"Going forward, knowing that life can survive in hydrogen, researchers could expand their observations of far-off exoplanets and their atmospheres."

Before going too far forward, it might be advisable to understand if life could even arise in a hydrogen-rich environment. Placing life from a 20% oxygen atmosphere (highly reactive) under hydrogen and watching them survive for any length of time is not very demonstrative.

Abiogenesis as occurred on earth, with regard to the atmosphere, must have had certain limits on a bio-essential chemistry. What those limits are is certainly unknown, but extremes can be ruled out, Any limits would likely include a range of acceptable atomic and molecular components in the exo-atmospheres where life might arise abiotically.

Assuming hydrogen-rich atmospheres are conducive to life (reasonable probability), its mere presence in any exoplanet does not mean the conditions could or could not give rise to life. There are other elements and compounds which could "poison" the atmosphere, possibly at levels which would escape detection. One should obtain as much information as to composition of any exo-atmosphere to reasonably predict a probability of abiogenesis and the presence of life.

Sulfuric acid, such as observed in the atmosphere of Venus, would be only one of many obstacles.
 
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Mar 19, 2020
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"And.. have we found life on Mars?"

For some, a more appropriate question might be:

"Have we found any evidence for life having existed on Mars?"

That one has a very clear answer: No
 
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Feb 3, 2020
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Quoting from the article:

"Going forward, knowing that life can survive in hydrogen, researchers could expand their observations of far-off exoplanets and their atmospheres."

Before going too far forward, it might be advisable to understand if life could even arise in a hydrogen-rich environment. Placing life from a 20% oxygen atmosphere (highly reactive) under hydrogen and watching them survive for any length of time is not very demonstrative.

Abiogenesis as occurred on earth, with regard to the atmosphere, must have had certain limits on a bio-essential chemistry. What those limits are is certainly unknown, but extremes can be ruled out, Any limits would likely include a range of acceptable atomic and molecular components in the exo-atmospheres where life might arise abiotically.

Assuming hydrogen-rich atmospheres are conducive to life (reasonable probability), its mere presence in any exoplanet does not mean the conditions could or could not give rise to life. There are other elements and compounds which could "poison" the atmosphere, possibly at levels which would escape detection. One should obtain as much information as to composition of any exo-atmosphere to reasonably predict a probability of abiogenesis and the presence of life.

Sulfuric acid, such as observed in the atmosphere of Venus, would be only one of many obstacles.

Question: How much evidence is there that Abiogenesis occurred (or not) on earth?
 
Mar 19, 2020
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If you reject god(s) and seeding from other sources, the evidence for abiogenesis occurring on earth is overwhelming. Logic asks the obvious : "How did life arise?" (On a planet that was once "sterilized" by its very formation.)

Almost no self-respecting scientist would tell you that a magic wand made it happen. And seeding without space ships is highly improbable. High probability mechanisms often over-rule low probability alternatives simply by deductive reasoning. A clear understanding of the science involved is critical to this understanding.
 
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rod

Oct 22, 2019
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"the evidence for abiogenesis occurring on earth is overwhelming." There is no fossil record evidence that shows the first ancestor of the fist living cell was non-living matter. The fossil record from Precambrian, Cambrian explosion, and Cenozoic records biogenesis at work along with death, massive death in the strata. we have more than 4200 exoplanets documented. None are shown to have abiogenesis at work on them or even a fossil record, this includes Mars. We can test the *overwhelming* by comparing to the work of Galileo against the geocentric astronomy. Galileo documented 4 lights moving around Jupiter that contradicted the geocentric astronomy. Today, more than 400 years later, we can still see those 4 Galilean moons orbiting Jupiter. This is an excellent example of overwhelming evidence used to show geocentric astronomy was wrong but there is no comparison of 400 years or more observing abiogenesis create new life on Earth, thus the claim seems more like hype then factual science that is verified like Galileo's work. This is how the scientific method works, Galileo observations has withstood more than 400 years of testing.
 
Feb 3, 2020
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I've been laboring under the impression that the most likely source of life on this planet is seeding. Not from travelers, but random pieces of rock or ice that just happened to land here. That said, I've heard discussion about the possibility that life began "spontaneously" near under-sea thermal vents. I gather this is abiogenesis?

I'm open to thoughts.
 
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Mar 19, 2020
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I've been laboring under the impression that the most likely source of life on this planet is seeding. Not from travelers, but random pieces of rock or ice that just happened to land here. That said, I've heard discussion about the possibility that life began "spontaneously" near under-sea thermal vents. I gather this is abiogenesis?

I'm open to thoughts.

Life arising from an alien source (off-earth) only puts the origin of life somewhere else. It has to start in some way, either by natural processes (i.e. "abiogenesis" - from lifeless chemicals), or by supernatural means (i.e. "the magic wand" - choose anything you like - no proofs required!).

For the term "spontaneous", one definition is of a rapid event, occurring quickly - almost immediately some might say. This would be highly unlikely for the process of abiogenesis. It is simply not a rational concept based on life's extreme complexity. Such spontaneity falls under "supernatural means".

But "spontaneous" has other meanings, and one of these is most appropriate for abiogenesis: "occurring without apparent external cause" - that is, a natural event occurring on-earth (a magic wand need not apply).

For those of us who are fans of real science and what it all means, abiogenesis* is the most logical and rational approach because it relies on well defined chemical interactions, many found in standard chemistry books, particularly organic chemistry. Many of the reactions and interactions that occur in life are already known to occur in the absence of life. This clearly provides a solid, logical foundation for abiogenesis.

To be sure, laboratory experiments demonstrate that some of the fundamental building blocks of life, such as amino acids, can be produced by a simple mixture of chemicals subjected to energetic sources (lightning, radiation, etc.). Such experiments provide the best approach to establishing an origin of life, assuming logic is the primary driver of rationale and reasoning on this subject.

The devil, as it were, is in the details of how all this complexity arose. But that it arose without outside interference is accepted by almost everyone who works in the sciences - for obvious reasons.

An old, alternate concept of how life arose is known as "Spontaneous Generation". This notion suggested that all life simply popped up everywhere, and anywhere. Like magic! You just had to "catch it in the act" to prove this notion was correct. Such origins of life were largely disproven by Pasteur and Tyndall in the 1800s. Even a below-average grasp of logic dictates that Spontaneous Generation as the origin of life is simply not possible.

To be sure, the old and dead concept of Spontaneous Generation is in NO WAY associated with abiogenesis, and anyone suggesting otherwise is sadly mistaken.

* https://en.wikipedia.org/wiki/Abiogenesis
 
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rod

Oct 22, 2019
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FYI, wikipedia has an interesting article on the scientific method, https://en.wikipedia.org/wiki/Scientific_method There are 10 references to falsifiable, falsify, used. Louis Pasteur experiments falsified spontaneous generation for the origin of life. In my studies, I have not seen any reports that document abiogenesis is creating new life on Earth today, e.g. Charles Darwin warm little pond. What test(s) today using the scientific method like Louis Pasteur experiments, can be performed to show that abiogenesis *never took place on Earth*, in the unobserved past?
 
Feb 19, 2020
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Has anyone considered that this discovery means we have already possibly contaminated both Jupiter and Saturn with the Galileo and Cassini probes? Our understanding was that life did not and could not exist in their atmospheres, which made them safe to crash our spacecraft into in order to avoid contaminating Europa or Enceladus. In light of Seager's team's discovery, this certainty is now in doubt, and the potential spread of Earth organisms cannot be ruled out. What does Planetary Protection have to say on this matter? Have they issued a statement?
 
Mar 19, 2020
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Has anyone considered that this discovery means we have already possibly contaminated both Jupiter and Saturn with the Galileo and Cassini probes? Our understanding was that life did not and could not exist in their atmospheres, which made them safe to crash our spacecraft into in order to avoid contaminating Europa or Enceladus. In light of Seager's team's discovery, this certainty is now in doubt, and the potential spread of Earth organisms cannot be ruled out. What does Planetary Protection have to say on this matter? Have they issued a statement?
While it is very unlikely that any living microbe from earth could have survived on the outside of these spacecraft during their entire missions, it cannot be ruled out that spores of bacteria, etc. could have survived inside. There are a lot of places that such spores could hide, since, if the electronics were working when they were de-orbited, that "environment" prior to entry must have been semi-stable at the very least.

However, keep in mind that these probes were sent into these atmospheres at high speeds, and they almost certainly attained very high temperatures (i.e. burned up) during these encounters, which would sterilize all of the residue as they disintegrated.

All things considered, contamination of Jupiter and Saturn seems highly unlikely.
 
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May 8, 2020
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I this discussion I would like to say that our universe and the stances towards the term "our universe suggest you already know that there are more then one universe . hence the term our universe if you only believe din one universe it would be the universe. however I agree with you as a forward thinking scientist (citizen). yes I actually could also say that some universes are not hydrogen 75 per cent and helium 25 per cent in fact there is no hydrogen or helium . and the latest consensus, that code for me. would say it is because out universe is actually yon top of massive quantities of calcium based lifeforms that have died. if you want the map just ask
 

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