The discovery of all five nucleobases on Ryugu strengthens the idea that life’s molecular ingredients formed in space before reaching Earth.

A new study reports that samples from the asteroid Ryugu contain all five fundamental nucleobases, the molecular “letters” of life.

Tiny asteroid grains can preserve chemical clues about the ingredients that may have helped life emerge on Earth. The Ryugu material was returned from space in 2020 by the Japan Aerospace Exploration Agency’s (JAXA) Hayabusa2 mission.

In 2023, an international research team reported finding uracil, one of the nucleobases, in the Ryugu samples. Now, a study published on March 16, 2026, in Nature Astronomy by Japanese scientists has confirmed that all five nucleobases are present in the pristine asteroid material.

The finding suggests that these life related ingredients may have been common across the young Solar System…

  • skibidi@lemmy.world
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    1 天前

    Energy is an issue for theories of life on Pluto. The sun is incredibly faint, irradiance of 1/1600th that on Earth, so photosynthesis likely isn’t feasible.

    Pluto is quite small, and therefore almost certainly is geologically dead (no molten core - the heat has already escaped) like Mars - so thermal vents are also unlikely to be widespread.

    Pluto has a low density for a rocky world, about 50% less than the moon, so the heavier radioactive elements cannot be present in large amounts (as would be predicted from its position high up in the system’s gravity well).

    So, with poor prospects for photosynthesis, poor prospects for geothermal energy availability, and poor prospects for radioactive decay - where would simple Cthonian lifeforms get their energy from?

    • TropicalDingdong@lemmy.world
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      1 天前

      I think have completely misunderstood whats being said. I’m not talking about life evolving on pluto whatsover. I’m talking about precursor chemcicals for the evolution of life building up on pluto. And not through heat coming from the core of Pluto, but through surface chemistry happening from the repeated warming and cooling cycles of volitile ices on the planets surface as it passes around the sun. The relatively recent missions to Pluto confirm that there is strong evidence of an active geology on Pluto, but not one based on molten rock; one based on volitile ices (n2, n3, no3, co, c4, etc…), species which would be extremely short lived at earths surface temperature. This is evidenced by un-cratered areas across the surface where fresh ice has been deposited, compared with cratered areas which have suffered asteroid impacts. The proposal is that as Pluto comes close to the earth, these ices sublimate, and cause ice volcano eruptions, and then precipitate. But the idea of an active geology also creates the opportunity for more complex mineral species to arise. So it might be possible in Plutos very different geological cycle, there is the possibility that these volatile ices can form more complex minerals, like small single units of DNA, RNA, etc. Not life, but precursor chemistry for life. This article is further evidence of that. Instead of a molten core and mantle process, imagine a surface geology of freeze thaw cycles which concentrate minerals. This same process/ principal could apply to asteroids. They might undergo a freeze thaw cycle with the volatile ices at their surface, which could create a mineral cycle resulting in the concentration of organics.

      The part I’m coupling it with is other research that has recently demonstrated that hydrothermal vents tend to pop up where major asteroid impacts have occurred. Basically, several large lakes with hydrothermal vents as a result of an asteroid impact. I think also the crater in the gulf of mexico.

      So imagine the following scenario. An asteroid has been circling around some where in the solar system for hundreds of millions of years. Its big enough for a freeze thaw mineral cycle and organic precursors have been piling up for thousands of millennia; not life, but bits of the stuff of life. Then, bad luck day. It get its orbit perturbed in some manner, and its orbit ends up in a collision course with earth. It slams into a land surface some where. It forms a large crater, and because its a large crater, it forms a lake inside. At the bottom of the lake are hydro thermal vents.

      We’ve now solved for most of the major challenges of abiogensis. Where do the precursors come from (a mineral cycle we’re just learning about)? How do we concentrate them sufficiently (asteroid impacts which create craters)? And how do we introduce something which can support a novel chemical cycle which can further concentrate and accumulate chemistry to the point where even more complex molecules can arrive (proteins, DNA proper/ RNA proper, lipids, etc…).

      • Zedd_Prophecy@lemmy.world
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        1 天前

        You haven’t gotten any upvotes for this but I hope it’s because like me- I assume this is a viewpoint a lot of us think is definitely possible and so much so I’m surprised we havent fully proved at least the basics of it yet.

        • TropicalDingdong@lemmy.world
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          1 天前

          Is what it is. I have a biology degree and took evolutionary biology coursework in graduate school. I didn’t go that direction in terms of career but I’ve kept up with it at a “more than ley” distance ever since, because its obviously super interesting. The classes I took were when I was in a paleobotany lab and it was a big part of my life for a while, now, not really at all beyond reading the papers and asking annoying questions to NASA scientists like “can I have your data?”.