Earlier quoted context omitted.
Huh? Those smaller rocks would be even more irradiated, as they have no atmosphere? They’d also have to contend with re-entry.
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"The simple truth" being Genesis, for which there can be no evidence possible?
Ryugu asteroid samples contain all DNA and RNA building blocks
81–90 of 180 posts
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#82Earlier quoted context omitted.
Huh? Those smaller rocks would be even more irradiated, as they have no atmosphere? They’d also have to contend with re-entry.
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One thing I do agree with you: answering that an invisible dude did everything we don't get is much simpler indeed. Calling that a truth though.
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#83Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#84Earlier quoted context omitted.
Well the competition might be too fierce for any new life to develop
We could artificially create a sterile, large pool of the ingredients and see what happens. I've read about experiments like this but only at lab beaker scale.
The biology equivalent of "infinite monkeys at a typewriter"
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#85One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…
Comets is where many astronomers have long thought the ocean came from. Comets are literal drops in our ocean. LOTS of comets. The atmosphere and the Earth at large would have been very different, and being bombarded by many giant space snowballs (along with asteroids) would have contributed materials. The missing part is, um, missing. We still do not know. However, these samples contained building blocks, not actual self-replicating RNA. That might seem like nothing, but before this discovery, we thought they only contained one ingredient.
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#86One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…
> I'm no expert but this sounds strange.
A cynic might suggest the theory might exist because nobody could figure out how life got started on its own on earth.
The thing is I've never found the asteroid theory particularly satisfying either because it simply inserts another abstraction layer, explaining the problem away rather than explaining it.
That's not to say it's wrong but, in its current incarnation, it's just a bit meh.
I suppose perhaps that's part and parcel of it being a very hard problem to solve.
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#87How are samples collected? In space or as debris?
From near the start of the article: "In 2014, the Japanese spacecraft Hayabusa-2 blasted off on a 300-million-kilometer (185-million-mile) mission to land on Ryugu, a 900-meter-wide (2,950-feet-wide) asteroid. It successfully managed to collect two samples of rocks weighing 5.4 grams (under a fifth of an ounce) each and bring them back to Earth in 2020."
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#88Earlier quoted context omitted.
The smaller rocks are composed of those materials in solid state (e.g., ice not water). They are less irradiated as they are further away from the Sun (think the asteroid belt and beyond). Atmospheric entry (if that's what you mean) is irrelevant. What matters here is the transport of materials from a place where they could have formed, to a place where they couldn't.
Atmospheric entry is completely relevant because some people have made the illogical claim that meteorites falling on Earth could have contributed with such complex organic substances, like the nucleobases, to the appearance of life on Earth. The icy bodies from the outer Solar System that contain such organic substances are very easily vaporized during entry in the atmosphere of the Earth, so only a negligible fract…
Wouldn't a big enough asteroid have an inner part which survives entry? You seem to be saying that it's impossible for any meteorite that might have these chemicals to not be completely vaporized which seems doubtful. Have you got a source?
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#89Earlier quoted context omitted.
Yeah, but it seems impossible to experiment on the scale that would have happened in nature where there would have been millions of localized "test tube experiments" ongoing for millions of years. Of course people can, and do, try to replicate early earth environments and self-assembling proto-cells, but I'm not sure how intellectually satisfying any self-replication success from these "designer experiments" would be…
My personal theory is that the conditions for life are plentiful in the universe but it probably took an unbelieavable number of random chemical/mechanical events to form the first proto-lifeform. The discovery comes after these building blocks of life were detected on another asteroid called Bennu, suggesting they are abundant throughout the solar system. Yet actual life remains to be discovered...
Also it seems that finding a balance where an ecosystem doesn’t kill itself with its own waste is probably harder than we assume. Earth life has totally changed the atmosphere of the planet, I would many it many cases even when life does for it kills itself early on
Re: Ryugu asteroid samples contain all DNA and RNA building blocks
#90One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…
This theory is called panspermia [1] and it has several alternatives. One of the most extreme is that in the very early Universe, these building blocks could spread easily because the ambient temperature of the Universe was significantly higher than it is now. This isn't the most popular version. The most popular is that asteroids and other interstellar bodies spread the building blocks, be it anywhere from amino aci…
Paints the picture of an early solar system that was a fairly connected system. Perhaps life didn’t form anywhere but Porto-life formed everywhere and earth is the only place that hasn’t died yet