Ceres Earth Moon size comparison

The endless debate over NASA’s next destination resembles a food fight between the Moonmen and the Mars advocates. The near Earth asteroids get no respect from either side. That lack of respect seems kind of strange, considering some near-Earth asteroids have a potential ability to destroy all life on Earth. One would expect that sort of death-dealing ability to merit at least a little respect. Nevertheless, near-Earth asteroids are ridiculed as mere “rubble piles” and any proposed visit is a “mission to nowhere.”

Ultimately, this debate is silly. The only real answer to the designation question is “All of the Above.” If we develop low-cost access to space, supporting infrastructure such as propellant depots, and deep-space exploration exploration ships like JSC’s proposed Nautilus-X, we can go anywhere in the solar system. Without such capabilities, we’re going nowhere.

Having said that, let’s play the destination game just this once. We’d like to put in a pitch for a dark horse candidate.

The main-belt asteroids are seldom mentioned as potential targets for human exploration. There’s a good reason for that. The main asteroid belt is quite a ways off – on the other side of Mars – and if one wants to visit an asteroid, there are plenty of candidates in the near-Earth zone.

One main-belt asteroid stands out as an object of interest, though: the largest of the asteroids, Ceres. In fact, some planetary scientists don’t consider Ceres an asteroid at all but a dwarf planet, which may have been formed by a different process. In either case, Ceres is definitely interesting – the sort of place NASA should consider going.

Ceres is only about 1% the mass of the Moon, but has a surface area 7.5% as large as the Moon’s. That might not sound like much, but it’s an area 10 times the size of Texas. It’s also 10 times the total surface area of the Great Lakes. Beneath the thin, dusty surface covering is a layer of water ice that’s estimated to be 45-75 miles deep – 6-10 times as deep as any ocean on Earth. That’s a huge potential resource, larger than the total volume of fresh water on Earth, and dwarfs the amount of water which lunar scientists optimistically hope to find on the Moon.

More intriguingly, Ceres may not be a dead world. It has been suggested that Ceres may still have hydrothermal activity and even liquid oceans beneath its frozen crust. If that’s the case, then Ceres, like Europa, might even have life. In fact, Ceres might be a more promising abode for life than Europa, which orbits within Jupiter’s powerful radiation belts. Astrobiologists are now trying to determine how deep life would have to be to survive on Europa. Ceres has no such problem.

Considering the formidable technical problems involved in building a probe that can travel all the way to Europa, operate within the radiation belts, and still drill through miles of ice, it might make more sense for astrobiologists to check out Ceres first. Especially if the complexities of the drilling project prove too great for robots alone and require humans for on-site supervision.

Do we believe Ceres will be the next destination humans visit inspace? No. Ceres is not as far away as Europa but it is considerably farther than the Moon, the near-Earth asteroids, or even Mars. We can debate the merits of chemical versus nuclear propulsion for human missions to Mars, but Ceres clearly requires some sort of nuclear or electric propulsion. Nevertheless, it is worth keeping in mind as a mid-term option.

Written by Astro1 on March 30th, 2012 , Astrobiology, Space Exploration (General) Tags:

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COMMENTS
    J Lomas commented

    Good idea… Though using a NEP version of NauilusX would be a better option due to the size of the solar array that may be needed. Relatively expensive at $4-5bn dollars, given a conventional/SEP estimated build of $3.5-4bn build… Still a ‘can do’ mission if thought about/done correctly. Technology is out there…

    Reply
    March 31, 2012 at 11:59 am
    Chris Landau commented

    This article is written as though the Dawn Spacecraft probe that is presently orbiting the planet Vesta in the ” Asteroid belt” does not exist. The article seems to be written in a “wishful desire style” with the hope that we would one day explore Ceres. Of course Dawn arrives at Ceres in 2015, driven by Xenon ion propulsion. I think there is a good chance for some life on Ceres. That much water on Ceres would be nice, but just guesswork at this stage. Life of some sort, I hope is a possibility. It appears to have an atmosphere and spins fast enough to generate some internal heat to keep some critters warm enough.

    Please raise your glasses for the toast to Ceres.

    Vesta is amazing so far. So much geological activity has and is taking place, especially in calderas, and volcanic dykes/dikes, complete with chains of black micrcalderas that are remolding the craters as they rework the surface. There is of course much more to this oblate spheroid than is presently being discussed.

    Chris Landau (geologist)
    March 31, 2012

    Reply
    March 31, 2012 at 2:17 pm
      admin commented

      There may be life on Ceres, but there is no evidence of life aboard the Dawn space probe. Certainly not human life.

      Reply
      March 31, 2012 at 2:43 pm
    Bill Hensley commented

    Actually, Ceres is only about 4 times the surface area of Texas. Don’t mess with Texas, son. 🙂

    Reply
    March 31, 2012 at 4:29 pm
    Tom Billings commented

    A particularly attractive possibility for Ceres’ water is that it may have many salts in it. If so, the the light metals these salts often contain here on Earth may be duplicated there. These could be an early boon to the economy of the inner Solar System, in particular the Moon, which has Calcium in sufficient abundance, but little of the more volatile light metals.

    Even if it is frozen, and deeper than is convenient to mine from the surface, we can mine it the same way Sulfur is mined in Texas, by pumping heated water in, and getting melted ices out. When the cavern of ice gets large enough, drill a larger hole, and move settlers into the thing, then drill down and out from there opening up new volumes for settlement.

    In addition, organic salts would contain Carbon in forms even more easily obtained than in Carbonaceous Chondrite asteroids. Now, if only a little of that water has leaked to the surface, or been uncovered by collisions, if frozen, then Dawn may be able to show us a true treasure chest. If it is uncovered by a collision, then sublimation by the bare ice may create caverns on its own, till the salts and other suspended less volatile components coat the surfaces exposed enough to stop the out-flow of H2O.

    As you say, not the first place, but a treasure chest, once the rest of the inner Solar System needs its resources.

    Reply
    September 21, 2012 at 12:05 pm
    Sean Deany commented

    Sound as as if your as serious about Ceres as I am. I have recently put up a blog page on the dwarf planet 1 Ceres and indeed am waiting impatiently for Feb 2015 when the DAWN probe arrives.

    Reply
    October 24, 2013 at 12:23 am