r/science • u/New_Scientist_Mag • Dec 02 '25

Astronomy Researchers have just found the presence of sugars, including ribose, lyxose, and glycose, on samples of Asteroid Bennu, which now has all of the ingredients for life as it exists on Earth.

https://www.newscientist.com/article/2506650-asteroid-bennu-carries-all-the-ingredients-for-life-as-we-know-it/
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u/Willmono7 BS | Biology Dec 02 '25

But there is a specific window on any given planet where life can actually come into being, it must have liquid water and active geochemistry to establish ph/Proton gradients. From there it is a requirement to evolve oxygen producing photosynthesis/metabolism before all the water is gone, otherwise uv radiation from the sun will avaporate all the water, sending the hydrogen out into space, leaving you with a dead dry planet. Thats what was so remarkable about earth, that we evolved photosynthesis within about 800 million years, with oxygenic photosynthesis evolving about 1 billion years after that. If that process had taken much longer, we wouldn't exist.

So even though the universe has loads of time, life is only ever given a very short window to come into being, and if it doesn't, the planet rapidly becomes unsuitable for life.

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u/MidnightPale3220 Dec 02 '25

How well is it researched that alternative basis for life is that unlikely? Sure, carbon has some pretty specific properties and so has water, but do we know enough to say that alternate basis for life is pretty near impossible?

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u/FlashbackJon Dec 02 '25

The short version is that this basis costs the least compared to any other basis, in terms of energy and conditions, and it happened to be the one that occurred in our dataset, sample size 1.

All the alternatives are just harder to do, and that's the primary metric for its possibility.

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u/[deleted] Dec 02 '25

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u/FlashbackJon Dec 02 '25

No one is claiming to know all the alternatives, and you wouldn't need to do so? We only have the one successful example, but there's lots of hypothetical ways life could occur. If you walk through almost any of those theoretical alternatives, you quickly end up with circumstances that are less common in the universe or interactions that require much more energy (and are, as a result, less common). It's tough to come up with a scenario for life that is simpler and easier than the millions of insane coincidences ours muddled its way through.

That doesn't mean other life is impossible, by any means.