Lots of ice on Ceres


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New data from Dawn now suggests that Ceres contains a large amount of ice on or near its surface.

“On Ceres, ice is not just localized to a few craters. It’s everywhere, and nearer to the surface with higher latitudes,” said Thomas Prettyman, principal investigator of Dawn’s gamma ray and neutron detector (GRaND), based at the Planetary Science Institute, Tucson, Arizona. Researchers used the GRaND instrument to determine the concentrations of hydrogen, iron and potassium in the uppermost yard (or meter) of Ceres. GRaND measures the number and energy of gamma rays and neutrons coming from Ceres. Neutrons are produced as galactic cosmic rays interact with Ceres’ surface. Some neutrons get absorbed into the surface, while others escape. Since hydrogen slows down neutrons, it is associated with a fewer neutrons escaping. On Ceres, hydrogen is likely to be in the form of frozen water (which is made of two hydrogen atoms and one oxygen atom).

Rather than a solid ice layer, there is likely to be a porous mixture of rocky materials in which ice fills the pores, researchers found. The GRaND data show that the mixture is about 10 percent ice by weight.

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6 comments

  • Orion314

    PLENTY for a future refueling station…IF ONLY…..

  • Alex

    Orion314: Maybe, but CERES orbit inclination is quite large (about 10°), which needs much delta-v.

  • DougSpace

    Dawn made the orbital inclination change using ion propulsion. Might the same be possible on a crewed mission?

  • LocalFluff

    Who is surprised? Ceres being made out of chocolate would’ve been a really great news.

    The center of Ceres, almost 1,000 kilometer in diameter, has no more pressure than the deepest active mine on Earth (a gold mine in South Africa). So it is just a matter of engineering and economy and time for us to rebuild all of Ceres to whatever we want it to be. Its mass is about a billion billion tons. Almost a billion tons of resources for each and everyone of us. Imagine one hundred shipping containers in a row. Squared. And stacked 100 on top of each others. And that is for you alone. (How stupid are those who cry about peak resource whatever!)

  • Alex

    LocalFluff: Are you shure? Keith Allpress says (Written Jan 30): The internal pressure rises to just below 0.2 GigaPascals. Or 30,000 psi. That equals about 2,000 bars, not much compared to Earth’s centre, but I assume much more as the rock in mine displays.

    DougSpace: Ion propelled manned S/C may need to long to reach Ceres (thrust is too small), better use advanced thermal nuclear propulsion and regain LH2 propellant at Ceres.

  • Edward

    I think that Alex has a good point about the delta-V needed for the 10° inclination change. My calculation shows that it is about 37%, which is close to the delta-V needed for escape velocity from the solar system, from the asteroid belt. This suggests that Ceres may not be practical as a refueling station.

    A better refueling station would be an asteroid that lies within/close to the plane of the ecliptic (my proxy for the plane of the average of all the planetary planes). If there is a lot of water on smaller asteroids, it may not be hard to find one or several of these potential refueling-station asteroids. This would make trips to the outer planets slightly easier, as the initial boost out of the inner planet’s orbit would require less fuel, thus a smaller rocket would be needed if it were refueled at the asteroid belt.

    LocalFluff,
    I agree. Planets, even dwarf planets, would be a high priority destination, if they were made out of chocolate.

    Mmm. Chocolate.

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