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Space

The Search for Alien Life Moves to Icy Moons (yahoo.com) 57

The search for life beyond Earth "follows the water," reports the Economist (since water is vital for earth's lifeforms, and the laws of chemistry are universal). "For most of the space age that insight led scientists to Mars." But... More and more, though, planetary scientists are following the water to other places — and in particular to the so-called "icy moons" that orbit Jupiter, Saturn, Neptune and Uranus, the solar system's quartet of giant gas planets. Many of those moons are either known or suspected to have oceans beneath their icy shells, kept liquid by gravitational squeezing from the planets they orbit.

On April 13th, if all goes well, a new spacecraft will blast off from French Guiana en route to Jupiter with the aim of investigating some of those watery moons up close. The European Space Agency's Jupiter Icy Moons Explorer (given the slightly contrived acronym "JUICE ") will slingshot once around Venus and three times around Earth before arriving at Jupiter in 2031.... JUICE will investigate three of the so-called Galilean moons — Callisto, Europa and Ganymede, all of which are thought to have subsurface oceans. (The fourth, Io, is arid, and so not of interest.)

Ganymede is the probe's primary target. Despite being a moon, it is bigger than the planet Mercury. Its subsurface ocean may contain more water than all of Earth's oceans combined. The probe's cameras will add much more detail to the existing, low-resolution maps of Ganymede's surface. An ice-penetrating radar will scan several kilometres below the ground. A magnetometer will take advantage of the fact that Ganymede, apparently uniquely among the solar system's moons, has a weak magnetic field that interacts with the much bigger field generated by Jupiter itself. The subtleties of that magnetic field were an early clue for the existence of an ocean, hinting at the presence of a large chunk of conductive fluid — such as salty water — beneath the surface. Better readings of the magnetic field will help scientists estimate just how big the ocean is....

Nor is JUICE the only probe on its way to Jupiter. Next year NASA will launch Europa Clipper, focused, as its name suggests, on Europa. Despite its later launch, it will take a quicker route to Jupiter, arriving a few months before JUICE . And, because there are limits to what can be discerned from orbit, both NASA and the Europeans are sketching plans for future landers that would descend to the surface of such moons to sample the seawater directly.

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The Search for Alien Life Moves to Icy Moons

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  • Uh oh (Score:4, Funny)

    by 93 Escort Wagon ( 326346 ) on Sunday April 09, 2023 @12:15AM (#63436044)

    "All these worlds are yours, except Europa. Attempt no landing there."

    Isn't that in the bible or something?

    • Re: (Score:2, Funny)

      by CaptQuark ( 2706165 )

      If your bible is Arthur C. Clark's book 2010: Odyssey Two, then yes.

      2010: Odyssey Two [wikipedia.org]

      • I thought it was odd that converting Jupiter to a star didn't kill the life the aliens were supposedly trying to nurture.

        Or life on earth, for that matter.

        • The smallest stars burn deuterium and glow a dull red.

          How would that harm life on Earth?

          • They're talking about Europa. If there's life there that's evolved to live on an icy moon, setting Jupiter on fire would probably not be great for it.

            • by Rademir ( 168324 )

              Jupiter becoming a star might warm Europa's surface enough for life to be fruitful and multiply up there. Counterpoint, red dwarfs tend to flare a lot. So unless the aliens did something to avoid that it will be an issue for any would-be surface dwellers.

              • They aliens were clearly very advanced, so we could imagine they could maybe create a stronger magnetic field that would still allow the oceans to be unfrozen at surface level. But I wonder in this thread of thought, would it change orbital dynamics in this new binary system they created...

              • Jupiter becoming a red dwarf would boil all of Europa's life. You don't want to be 417,000 km from the surface of a star. For comparison, Proxima Centauri b is about 20x further from its star and has a surface temperature probably similar to Earth.

                Regardless, Jupiter's radiation is already far too intense to survive on the surface of Europa. Making it a star isn't going to help that.

  • 2031 (Score:4, Informative)

    by l810c ( 551591 ) on Sunday April 09, 2023 @12:23AM (#63436052)

    It's just mind blowing that it will be 7-8 years to reach Jupiter in Our Solar System.
    I'm a Sci-Fi fan and watch most movies and TV series.
    But all of this entertainment is based on Fiction.
    Getting to our 5th planet is about the Science.
    Hoping for a successful journey.
    Possibly some future discovery/invention will lead us to explore other Solar Systems.

    • Re: (Score:3, Informative)

      This mission is taking the scenic route through the solar system. If there was a need to get to Jupiter in a hurry, it can be done. New Horizons was the fastest probe to leave Earth [gizmodo.com] and got to Pluto in less than ten years. It swung by Jupiter a year after launch.
      • Re: 2031 (Score:4, Informative)

        by Cochonou ( 576531 ) on Sunday April 09, 2023 @04:27AM (#63436206) Homepage
        The thing is that the New Horizon did not have to decelerate near Pluto as it did not enter its orbit but flew past it with all of its science instruments recording. Energy-wise, this makes a lot of things simpler, but of course it is not the same amount of science data gathered.
        • The thing is that the New Horizon did not have to decelerate near Pluto as it did not enter its orbit but flew past it

          Dark Probe : [as the ship is going into into interstellar speed] We've passed it. Stop this thing!

          Colonel Sandurz : We can't stop, it's too dangerous! We have to slow down first!

    • Possibly some future discovery/invention will lead us to explore other Solar Systems.

      "Solar" is Latin meaning "relating to Sol" which is the name of our star of which there is only one in the universe.
      "Stellar" is Latin meaning "relating to a star".

      Clearly you meant to write, "other stellar systems".

    • You can each it quicker if you want to spent more fuel, aka money, etc.
      But this "route" is using several "fly byes" aka "gravity assists" to safe fuel, compensated with travel time.

  • The more ancient, the better.

    I do like how they have the same "guests" on yet depending on the topic theme they give entirely different answers to the same question.

    For example, they have multiple Stonehenge episodes. In one Merlin created Stonehenge using a rod given to him by aliens, in another Merlin is an alien, in another the little green men in space ships aliens did it from their ships, in another Merlin is a sorcerer who uses ley lines to power his magic to do it, and so on.

    Great stuff and the inco

    • They haven't destroyed their world, so they can only be primative. /S

      But really, I think we'll find that life exists wherever the conditions are suitable. Each world, ours included, seeded from the swirling detritus of the solar system. Once any place is suitable enough for long enough, who knows, maybe even complex life (from a cellular not technological perspective) is ubiquitous and endemic across the galaxy.

      The next question, of course, is how do you serve it? Steamed or fried?

    • by rossdee ( 243626 )

      Stonehenge was around long before Merlin.

    • The more ancient, the better.

      I do like how they have the same "guests" on yet depending on the topic theme they give entirely different answers to the same question.

      For example, they have multiple Stonehenge episodes. In one Merlin created Stonehenge using a rod given to him by aliens, in another Merlin is an alien, in another the little green men in space ships aliens did it from their ships, in another Merlin is a sorcerer who uses ley lines to power his magic to do it, and so on.

      Great stuff and the inconsistencies make it even better.

      Most of their audience isn't noticing any inconsistencies. From the little bit I've watched, the show is based on "argument from personal incredulity". Or the concept that back in the day, humans were stupid and couldn't do anything.

      When it is pretty clear we could do a lot of things.

      For humanities obvious failings, we have some really impressive abilities. We can figure out how to build and move things around using "primitive" methods which are very clever. The Rope and log winch is one example. Or the

      • I get what you're saying and it's all true.

        I watch it for the hilarity of the inconsistencies in logic yet consistency in "it must have been aliens!!! Moving big rocks was too hard!"

        Quite the opposite of the show's theme, I think our ancestors were a lot more advanced than we give them credit for and not subsistence level berry eaters hiding from their own shadows.

        There are a *lot* of megalithic structures around the world and the shadowy remnants of very ancient cities that don't align well with current th

        • shadowy remnants of very ancient cities that don't align well with current theory about the development timeline of civilization

          Cite, please. I've watched this crap for over sixty years and haven't seen anything all that radical.

  • by backslashdot ( 95548 ) on Sunday April 09, 2023 @01:28AM (#63436094)

    Life formation is a highly low probability event. Even on Earth, life appears to have emerged only once. By phylogenetic analysis of the genomes of various organisms, it is clear that life can be mathematically/logically lineage traced back to one common ancestor (called LUCA - last universal common ancestor.) This is especially clear by the fact that the genomic code for the ribosome of all life is very similar (for example compare the 50S in all prokaryotes vs. 60S in all eukaryotes). All life on Earth is based on DNA (that's suspicious enough), and not only that, but all life on earth utilizes a very similar ribosome for translating DNA into protein. That seems VERY suspect. If life could come about easily, we should see non-DNA based life. Life based on mechanisms other than DNA->RNA->Protein. Life that uses a different ribosome. Imagine if everyone on a planet spoke the same language, you'd assume that inventing a language was a very difficult thing. The alternate possibility is that speakers of that language got rid of everyone who spoke a different language. But is that really possible when it comes to life? Surely there ought to be niches where life based on an architecture that isn't DNA->RNA->Protein, and at least not utilizing nearly the exact same ribosomal sequence code, hangs out? You are telling me that LUCA's descendents successfully wiped out all other types of life emerging? And no, LUCA descendents likely did not integrate those lifeforms .. because to integrate them requires transcriptional/translational compatibility.

    • *for translating RNA into protein

    • Yes, life formation is very unlikely, but once it has formed, life colonizes its surroundings extremely effectively and prolifically, as you have shown. Has it colonized other planets already? Did LUCA form on Ganymede, and hitched a ride to Earth somehow?
    • by Viol8 ( 599362 )

      "You are telling me that LUCA's descendents successfully wiped out all other types of life emerging"

      Why not? This isn't life competing in an ecosystem, its chemical reactions competing in a soup. Once a self reproducing chemical system really gets going it'll change the chemistry to suit itself and grab all the resources so out competing/strangling any other types of chemistry.

      • That means at the time of LUCA's emergence, and all time since, .. every area where life could form on Earth was and still is somehow connected and not isolated. Furthermore LUCA or an ancestor of LUCA had (or has) the capability of starving out or destroying those other life prototypes in every niche we've surveyed.

        • Life didn't start in every niche and life was around in microbial and unicellular stages long before it left its traces. The competition would have been contained at first. We have numerous examples of that happening on the levels of organisms. With the huge stretch of time before recorded life, it's possible.

          It's all supposition at this point.
    • by alvinrod ( 889928 ) on Sunday April 09, 2023 @12:46PM (#63436756)
      We don't know how many times life emerged or how frequently it occurs. We know that it's happened at least once and the records of if having occurred previously but dying out would be difficult to find given the time span and the extent to which that life grew beyond its genesis point. We also wouldn't have a good record of all of the times some life process has started since then either as it may have died out naturally, been destroyed by existing life forms before it ever got anywhere, or just have all occurred in a place where we're not looking.

      In a few hundred years I think we'll have learned so much that a lot of what we believe now will have drastically changed or will be called into question based on better hypothesis that we can actually test.
      • This. Once any particular self replicating biological life takes hold it quickly gains a monopoly in that environment. Life based on some other biochemistry but the same underlying chemistry has no chance to compete.
    • Life formation is a highly low probability event. Even on Earth, life appears to have emerged only once.

      However, as a counterpoint argument, abiogenesis on earth seems to have occurred practically instantaneously, once the geologic situation calmed down enough from the planet's formation. The almost immediate emergence of life once conditions became favorable argues that it isn't as low a probability event as you might imagine.

  • by backslashdot ( 95548 ) on Sunday April 09, 2023 @01:52AM (#63436114)

    Europa Clipper/JUICE are nice .. but the most awesome mission would have been Europa Lander .. would have been able to directly sample the surface not mention send back amazing photos of that ice world .. but the Trump administration cancelled it. Thankfully Biden restored funding for a lander mission, but it will now probably take another decade to even be launched.

    Reference: https://en.wikipedia.org/wiki/... [wikipedia.org]

    • by pcaylor ( 648195 )

      I don't want to defend Trump, but faces are facts, and the Wikipedia article you linked to says:

      The president's 2018 and 2019 federal budget proposals do not fund the Europa Lander, but they did assign US$195 million for concept studies and research on the required science instruments. The 2022 omnibus spending bill allocates $14.2 million to Icy Satellites Surface Technology for a future Ocean Worlds lander mission (Nasa had requested $5 million for the Europa Lander).

      If you are working on the project, whi

  • kept liquid by gravitational squeezing from the planets they orbit... How does that work?
  • I found this statement in the article intriguing: "Life is self-organising chemistry". Here's some more information on this [wikipedia.org].
  • The amount of radiation Europa is exposed to is insane. Per Wiki, the surface gets about 540 rems per 24 hours.

    I know bacteria are tough, and they're planning to look below the surface for life. But with that radiation, I'm be surprised if life ever had a chance to start there period.

    • Yes, but the radiation cannot penetrate too far into Europa's icy shell or its ocean. A bigger concern, at least form my perspective, is sulfuric acid; Europa gets dosed with sulfur from Io and the icy surface gets recycled. How much of that turns to acid and now acidic is the ocean?
  • Life also needs a decent energy gradient and it doesn't look like there'll be much of one inside an icy moon.

    • I am not so sure of that. Look at what is happening on Earth alongside the deep ocean trenches; plenty of life there, and I imagine that there are vents like that on the icy moons.
    • The gradients are steep enough to keep Europa cracked, Ganymede magnetic, and Io covered in basalt, so your standard anaerobes don't seem like too tall an order.
  • This is one of my favourites... https://www.smbc-comics.com/co... [smbc-comics.com]

As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality. -- Albert Einstein

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