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Rob Sheldon on Earth-like conditions and life

Dr Sheldon
Rob Sheldon

Further to NASA says new Earth-like planet found (which may or may not be actually Earth-like), the question was raised, “Is there an accepted hypothesis on the subject of whether Earth-like conditions are essential to life?”

Physicist Rob Sheldon writes to say,

Like most other things involving life, NASA is schizophrenic about the subject.

Darwinists say that life ought to be springing up everywhere that conditions permit. But then when their initial exuberance is not rewarded, the excuse is that conditions are not permitting. But Darwinists can’t have it both ways. Either Origin-of-life (OOL) is tough and the Earth is miracle, or it is easy, really really easy and Earth is nothing special. If life sprang up on Earth between 3.85 billion and 3.65 billion years ago, then 200 million years is sufficient time for OOL. Some would even shrink that range of time to 100 million years or less. Mars had oceans for at least 200 million years. Why doesn’t it have life? Europa still has oceans 4.5 billion years later, why doesn’t it have life? Questions that none of the Darwinists can answer.

Well how do we know it doesn’t? It turns out that biomarkers–complex molecules like nucleotides, amino acids, phytanes–have been found in these places. So there is increasing evidence that life really does exist throughout the solar system. (I happened upon a slide from the Huygens probe mass spectrometer that showed amino acids were present on Titan.) I have bored you before with the 2 dozen or 3 dozen biomarkers on Mars discovered by every lander since Viking in 1976. So why doesn’t NASA advertise it? You would think Darwinists everywhere would rejoice?

Instead, NASA has adopted the party line that Darwinism is true but OOL is really hard. Since Viking, it has explicitly written into its Mars research opportunities (AO/NRA) that it will only fund the search for life environments (e.g., water), but not the search for life itself. Even then, it takes a European Mars mission to pry out of NASA that it has seen water, snow, methane, chloromethane before. As many eyewitness accounts attest, many naive scientists researching Martian life have found themselves bound and gagged. The great irony is how many people gloat that NASA has not found life despite searching for it, when in fact, the true tale is the very opposite.

So back to the story, is life only possible on an Earth-like planet? Absolutely not. Titan isn’t earthlike. Europa and Enceladus aren’t earthlike, yet they have biosignatures. Comets don’t have gravity, yet they have fossils. We have found microorganisms on Earth that thrive at 130C, that live at -30C, that float in the stratosphere, that live 2 miles deep in the Earth’s crust. We’ve found life that lives on sulfur metabolism, life that lives on frozen methane. Life has some pretty amazing capabilities with broad limits but an “Earth-like” planet isn’t one of them.

So what is this claim that Earth-like planets are needed for OOL? Well, if we had the faintest idea for a theory about OOL, we might make this claim, but this is just a rehash of the widely discredited “warm little pond” or “drying out tidal pool” argument. But not only is such a OOL theory discredited, it isn’t even necessary. If life can live on comets–as we know from the fossils–then OOL need only happen once, and everywhere else is an infection, excuse me, a colonization. That makes Earth-like planets simply oases in the well-travelled paths of the galaxy.

The impression one gets is that we haven’t the certainty we would need to be so certain as some news releases sound.

See also: Why origin of life is a difficult question

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REC 7 “Comets don’t have gravity, yet they have fossils.” "Some comet somewhere might–however unlikely, have a fossil. ALL comets EVERYWHERE have gravity. That is the more shocking mistake–especially from a physicist." ----------------------------------------------------------- So you honestly believe that Dr. Sheldon, a physicist, is unaware that comets do have very tiny gravity? So little that you could easily jump off at escape velocity? You're joking, right? Right? anthropic
Mapou, Thanks, you might be right. However, the paper does say:
The Orgueil CI meteorite, which may be a remnant of a comet, has been found to contain abundant microfossils of mineralized cyanobacteria (Fig. 3c & d) surrounded by high carbon (kerogen) sheaths.
From the context, it looks like the authors are considering bacteria being transferred from Earth to the comet in a collision, as you described, and possibly surviving for some time in space. Edit: Anyway, to be fair to Dr Sheldon, maybe there is other research providing stronger evidence of microbes living on comets? I really doubt there's anything conclusive though. That would be sensational. daveS
daveS @9, That paper does not seem to claim that fossils have been found on comets but that comets may be able to harbor microbial life. This is weird since Sheldon is one of the authors and should know what the paper is claiming. Mapou
It is possible, although unlikely, for a comet to have fossils. Such fossils would likely be of terrestrial origin on account of a primordial collision between said comet and planet Earth. Mapou
Come to think of it, I've seen this claim before. See page 13 of this for a photo. And yes, Wickramasinghe is a coauthor. daveS
Perhaps he meant to say- "Comets don't have gravy..."- we all know fossils come with gravy, except on comets. :) Virgil Cain
Hate to say it, but what y'all are going on about is only the second worst part of the statement: "Comets don’t have gravity, yet they have fossils." Some comet somewhere might--however unlikely, have a fossil. ALL comets EVERYWHERE have gravity. That is the more shocking mistake--especially from a physicist. REC
Comets have fossils? That would have been the greatest news on Earth since the fall of Rome. I think Sheldon's grey matter is beginning to malfunction. Mapou
beau, That's what I want to know. (I don't believe any exist!) daveS
If life can live on comets–as we know from the fossils
Is there a reference for this? Thanks Jim Smith
Dave, what comets have undisputed microbial fossils? beau
id I miss some big news?
No, I think Sheldon is just displaying about his normal knowledge:pontification ratio. wd400
The great irony is how many people gloat that NASA has not found life despite searching for it, when in fact, the true tale is the very opposite. *** Comets don't have gravity, yet they have fossils.
What?! Did I miss some big news? daveS

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