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Space NASA

Planet Ceres Is An 'Ocean World' With Sea Water Beneath Surface, Mission Finds (theguardian.com) 90

The dwarf planet Ceres -- long believed to be a barren space rock -- is an ocean world with reservoirs of sea water beneath its surface, the results of a major exploration mission showed on Monday. The Guardian reports: Ceres is the largest object in the asteroid belt between Mars and Jupiter and has its own gravity, enabling the Nasa Dawn spacecraft to capture high-resolution images of its surface. Now a team of scientists from the United States and Europe have analyzed images relayed from the orbiter, captured about 35km (22 miles) from the asteroid. They focused on the 20-million-year-old Occator crater and determined that there is an "extensive reservoir" of brine beneath its surface.

Using infrared imaging, one team discovered the presence of the compound hydrohalite -- a material common in sea ice but which until now had never been observed off of Earth. Maria Cristina De Sanctis, from Rome's Istituto Nazionale di Astrofisica said hydrohalite was a clear sign Ceres used to have sea water. "We can now say that Ceres is a sort of ocean world, as are some of Saturn's and Jupiter's moons," she told AFP. The team said the salt deposits looked like they had built up within the last 2 million years -- the blink of an eye in space time. This suggests that the brine may still be ascending from the planet's interior, something De Sanctis said could have profound implications in future studies.

Writing in an accompanying comment article, Julie Castillo-Rogez, from the California Institute of Technology's Jet Propulsion Laboratory, said the discovery of hydrohalite was a "smoking gun" for ongoing water activity. "That material is unstable on Ceres' surface, and hence must have been emplaced very recently," she said. In a separate paper, US-based researchers analyzed images of the Occator crater and found that its mounds and hills may have formed when water ejected by the impact of a meteor froze on the surface.

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Planet Ceres Is An 'Ocean World' With Sea Water Beneath Surface, Mission Finds

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  • by spth ( 5126797 ) on Tuesday August 11, 2020 @02:08AM (#60388299)

    Like Pluto, Ceres was once considered a plant, but it was later decided that it should be classified as a dwarf planet instead.

    However, for Ceres this happened about 50 years after discovery, while for Pluto it took about 70.

    • Ceres, like Eris, always was considered a dwarf planet. Because it is "just a big asteroid" and is not orbiting in planes/orbits like the bigger planets.

      • by Rei ( 128717 )

        Nature has left a pretty clear dividing line between two classes of celestial bodies, and it's whether they're in hydrostatic equilibrium or not. The latter is comprised of primordial materials and is the sort of place you'd go to learn about how the solar system formed. The former is heavily modified by heat, fluids, tectonics, etc, and is the sort of place you'd go to learn about planetary geology and to search for life.

        Ceres is in hydrostatic equilibrium.

        • by ceoyoyo ( 59147 )

          Ceres is classified as a minor planet today for the same reason Pluto is: we like having a number of planets that's small enough to count without taking our shoes off. And some BS about "clearing their orbit".

          • by Rei ( 128717 ) on Tuesday August 11, 2020 @09:18AM (#60388947) Homepage

            "Ceres is classified as a minor planet today" because 6% of the IAU, an organization primarily dominated by astronomers and not planetary scientists, voted on the final day of a 10-day conference in 2006 to change the definition, after most of the people who opposed the "clearing its neighborhood" had already left because the planet-classification proposal looked to either be going nowhere or settling on a hydrostatic equilibrium definition - leading to such a lasting resentment among a lot of planetary scientists that some literally just ignore the IAU definition and continue referring to them as planets in peer-reviewed literature, and the reviewers do nothing to reject such references.

            One of the ironies is that the very person who coined the term "dwarf planet" - Alan Stern - is one of the IAU decision's biggest opponents. Just like with dwarf stars, dwarf galaxies, etc, he intended a "dwarf planet" to be a subcategory of "planet" - but they took his term and twisted it, in a grammatically-ridiculous way at that.

        • by spun ( 1352 )

          Ceres does not meet one of the three necessary requirement for being a planet, namely, it has not cleared it's neighboring region of planetesimals. It meets two: it is in hydrostatic equilibrium like you said, and it is not so big that some of it is undergoing nuclear fusion. But being in the asteroid belt, it fails the third criteria.

          • by Rei ( 128717 )

            The whole "clearing the neighborhood" notion is premised on a lie: that the planets cleared their own neighborhoods. They didn't. For example, Mars' neighborhood was cleared by Jupiter.

            Also, planets have tons of large objects in their neighborhoods. Neptune has friggin' Pluto in its "neighborhood".

      • Ceres, like Eris, always was considered a dwarf planet. Because it is "just a big asteroid" and is not orbiting in planes/orbits like the bigger planets.

        That is incorrect sir, and in the age of the Internet on mobile phones it's very sad indeed, that on a geeky forum people don't even bother to check wikipedia [wikipedia.org]:

        Classification

        The categorization of Ceres has changed more than once and has been the subject of some disagreement. Johann Elert Bode believed Ceres to be the "missing planet" he had proposed to exist between Mars and Jupiter, at a distance of 419 million km (2.8 AU) from the Sun.[26] Ceres was assigned a planetary symbol, and remained listed as a

    • When was Ceres considered a planet as opposed to a dwarf planet? My recollection is that for a long time, it was a really big asteroid. Later it was suggested that it might be spherical.
      • wikipedia [wikipedia.org]:

        Classification

        The categorization of Ceres has changed more than once and has been the subject of some disagreement. Johann Elert Bode believed Ceres to be the "missing planet" he had proposed to exist between Mars and Jupiter, at a distance of 419 million km (2.8 AU) from the Sun.[26] Ceres was assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno, and 4 Vesta) for half a century.[26][30][48]

        • 1) The very first sentence says there was "much disagreement". So it was never considered a planet by astronomers. 2) Bode suggested that based on the orbits of Mars and Jupiter, there could be a planet in between them. He was not the first to suggest this. He himself never suggested in 1772 that Ceres be designated as a planet as it was not discovered until 1801. Bode was right in that there was a large mass between the Jupiter and Mars. The discovery of other asteroids and the belt’s existence accou
          • Well, doesn't this clarify anything "Ceres was assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno, and 4 Vesta) for half a century."?
      • by spth ( 5126797 )

        From its discovery in 1801 until sometime into the 1850s.

        Though people used terms like "minor planet" rather than "dwarf planet" back then.

        • Some astronomers wanted it to be a planet however there was not general agreement that it should be classified as such. Part of it was the discovery of other large asteroids in the belt which would diminish the claim that Ceres should be considered a planet.
    • Like Pluto, Ceres was once considered a plant

      Really?
      I thought they were just big rocks.

  • by Viol8 ( 599362 ) on Tuesday August 11, 2020 @02:44AM (#60388325) Homepage

    Sea water implies a sea whereas this appears to be pockets of water scattered about. And its hardly surprising given that every reasonably sized icy body in the solar system seems to have at least some water beneath its crust and given ceres is considerably closer to the sun than most of them and so somewhat warmer its that much more likely for its size.

    • by DarkOx ( 621550 )

      The interesting implication is though that some of that ware might be liquid. I am not an expert in this area at all but my understanding is a lot of biologists and astrophysics people alike have some expectation that where there exists water in a liquid state there is a fairly good probability of at least very simple life forms being present.

      One of the somewhat unique things about Earth is we have temperatures and pressures that allow water to exist in three phases solid, liquid, and gaseous.

    • by ebvwfbw ( 864834 )

      If there's salt and liquid water in any type of quantity you can bet there's something living in it.

  • by feathersmg ( 1311045 ) on Tuesday August 11, 2020 @02:46AM (#60388329)
    Ceres is not yet declared a small Europa.
    From the original Nature article abstract: https://www.nature.com/article... [nature.com]
    "The surface and internal structure of Ceres show evidence of a global process of aqueous alteration, indicating the existence of an ocean in the past. However, it is not clear whether part of this ocean is still present and whether residual fluids are still circulating in the dwarf planet.".
    So, please keep calm and make science.
    • keep calm

      Fortunately for us all, you've managed to prevent mass hysteria with your insightful /. comment. I had already packed up the wagon and hitched the oxen to get to Ceres before all the water there had been laid stake!

  • Comment removed based on user account deletion
    • Unfortunately, with a mean density of only 2.16g/cc it seems to be mostly composed of water ice and light minerals - not the best building material. Though all that water could make it a valuable source of fuel and ecological supplies. For building massive space habitats though you probably want metal, or carbon with some advancements in graphene, etc. synthesis.

      Carbon is easy, most of the asteroids in the belt are carbonaceous. For metals, 16 Psyche appears to be the gem of the belt. It's only ~1% of th

      • by tragedy ( 27079 )

        Depends on what light minerals it has. Lithium, for example, is a pretty useful building material alloyed with aluminum and it very well might have significant quantities of aluminum. It's believed that Ceres has a lot of clay, so that makes aluminum pretty likely. Decent amounts of carbon are also pretty likely. Of course, there's no reason you would mine just Ceres. You would mine at multiple sites in the asteroid belt depending on what particular resource you want.
        Of course, being a large body whose surf

        • Sure, there's probably lots of useful minerals there that would be of great use if you wanted to found a new colony in the belt, where all that water and carbon would be immensely valuable.

          If your goal is to mine metals for other projects though - why would you choose to dig around in a dirty snowball looking for scraps, when there's a giant hunk of metal sitting right next door?

          • by tragedy ( 27079 )

            True. Ultimately it's going to depend on what's available at what location and where you need to use it. Ultimately we're going to need geological (right word?) surveys and definite plans of what we're actually going to build to know where the best places to mine are. All we're doing her is spitballing. It's nice to know that we shouldn't have too much trouble obtaining water, at least.

            • I believe "geology" specifically refers to Earth, so maybe asterology? Not to be confused with astrology, which won't be relevant until we are able to mine stars directly ;-).

              Once you're in the belt, pretty much everything is in very nearly the same "place" energetically speaking, relative to any of the planets. Meanwhile pretty much no two asteroids follow the same orbit, all having slightly different periods so that they don't maintain their relative positions, but instead pass each other every several

              • by tragedy ( 27079 )

                Energetically speaking it's all the same place, but it will take years to for the stream of materials to start arriving at any construction site. Not a big deal once the stream is moving, but it could change the start time of a project by years.
                You have a very good point that mining claims on large asteroids are going to be tricky. Especially considering that the claims could be three dimensional. With the very low gravity, you could dig a 587 mile mine tunnel right through the center of Ceres without much

                • >it will take years to for the stream of materials to start arriving at any construction site.
                  Yes, but unless you're building in the belt itself, it doesn't matter where in the belt you're mining from, it'll take roughly the same amount of time to get to anyplace outside the belt.

                  And there's not really any reason to build anything anywhere in the belt, except at the location you're actually mining the materials. You can't build nearby, because what's nearby is constantly changing. Unless you're going t

    • by cusco ( 717999 )

      I think we're a very long time from needing to construct O'Neil habitats. A faster, cheaper, better intermediate step is to use the very asteroids that we plan on mining as our habitat. Tunnel into the asteroid during mining, seal and insulate the walls of the tunnel, and fill it with gas. Asteroids rotate, so there is at least a minimal amount of centrifugal force to make plumbing and ventilation easier and let plants know which way is up. We'll have to figure out how to eliminate some of the negative

  • This leads me to elaborate the new law of fotonics: Resolution of the camera decreases following an the inverse square law for the ratio between the local and earth gravity. I now know why pictures from the moon are so low resolution.
  • Please prove life on other planets soon. I know it is statistically unlikely we're the only planet in the universe with life. That is unless you want to prove the bible right.
    • Pretty sure the Bible is silent about the existence or non existence of extraterrestrial life.

    • How will not proving life exists on other worlds means the Bible is right? That’s a false dichotomy. We know that the Bible has been very wrong in the field of astronomy in many regards: the universe does not revolve around the Earth. The existence of other planets other than Venus and Saturn in our own solar system is never mentioned. Stars cannot fall from the sky to the Earth as they are very far away, etc.
      • Gee, it's almost like the Bible was written hundreds of years ago by humans with an imperfect understanding of astrophysics and cosmology.

        Anyone looking to the Bible as some kind of true universal blueprint should have their head examined. I'd even extend it to "anyone interpreting the Bible in the most literal sense should have their head examined" - it is a historical work filled with metaphor that attempts to declare and define a set of philosophies.

        • by cusco ( 717999 )

          It's largely a fictional work, any actual accurate historical references are few and far between, fabrications and outright lies are far more common.

  • A planet is any gravitationally rounded body with a single core AND a regular structure such as strata.

    This had the advantage of working for extrasolar planets and rogue planets, issues the IAU definition never bothers with in its efforts to simplify astronomy in the classroom.

    If we go with a physical definition, rather than extrinsic transient properties, then Ceres should be considered a planet.

    I'm not thrilled by that but it now has all of the physical properties Earth does bar the specific diameter.

    If w

  • Uh, yeah. All mass has gravity, by definition. Didn't you learn that in sixth grade along with the rest of us?

    • by ceoyoyo ( 59147 )

      All *energy* has gravity. They don't really tell you that secret until university though.

    • Yes, but at some point it simply fails to exert any amount of force because the mass is simply too small, and the gravity immeasurable. But yes, gravity is a result of mass interacting with other mass. Phobos and Demos have shit for gravity. If there were oceans on mars I doubt you would experience a tidal effect. Definitely not enough to keep lighter gasses on the planet. Or your shit from floating away if you trip and drop your wrench as you fell.

  • This place needs an army of rovers to explore it. Chemicals we need to live obviously are available there. Very promising for a future space base.
  • by starless ( 60879 ) on Tuesday August 11, 2020 @08:01AM (#60388711)

    This article was amended on 11 August 2020. In an earlier version, the headline referred to Ceres as a planet, not a dwarf planet. In addition, rather than only stating that Ceres has its own gravity, the article has been amended to refer to the dwarf planet’s gravity in the context of having been rounded into a sphere.

    Although it's still not that well phrased...

    Ceres is the largest object in the asteroid belt between Mars and Jupiter, massive enough to be shaped by its gravity, enabling the Nasa Dawn spacecraft to capture high-resolution images of its surface.

  • by Dunbal ( 464142 ) * on Tuesday August 11, 2020 @10:16AM (#60389143)
    The duplicants will be happy. They're always running out of water...
  • "...has its own gravity..." This illustrates the level of scientific literacy among "journalists" reporting on science.

  • Pluto is 14x bigger, but Ceres is a planet?

    Sometimes it feels like scientists are just making a lot of hype for clicks.
  • Assuming we don't extinguish our species in the next couple hundred years, we'll need a Base out in the Belt for asteroid mining operations, and Ceres sounds like a great place to build one, then, especially if there turns out to be liquid water or at least water ice beneath the surface.
  • I predict, within a century, a century and a quarter at most, there will be wars over control of Ceres, given *water* out there.

    • But if you start the reactor you could free mars by melting mars ice core and produce a breathable atmosphere. Thats way better than Ceres. Plus mars has 3 breasted hookers.

  • It was Alderaan until Grand Moff Tarkin went and blew the damn thing up. That power hungry, technology stealing, bastard!

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