[X] My Assistant

[Decepticon]

Fans of Ceres will find this article interesting.

The 200 Plus Images are something I would love to get my hands on. Rotation animation Anyone!?


http://www.space.com/scienceastronomy/0509...res_planet.html

[Guest_BruceMoomaw_*]

The full "Nature" paper is now available at http://oposite.stsci.edu/pubinfo/pr/2005/27/pdf.pdf . (That double "pdf" at the end is no mistake.)

It turns out I made a dumb mistake by assuming that the "25% ice" figure was a reference to Ceres' volume, rather than its mass. Since ice is much lower density than rock, if that figure is for ice then the water-ice mantle on Ceres would have a bigger volume and thus be thicker than I had calculated. Sure enough:

"Assuming the densest core materials and the nominal mean density of 2,077 kgm23, ice mantles are 110–124km thick and constitute 24–26% of the body mass. The lighter core material requires a mantle thickness of 66 km and a 16% ice mass."

[Marz]

Thanks for the link and info, Bruce!

From reading, it almost sounds like Ceres is in its own class of 'roid, since it's the only one truly "relaxed". It's interesting that they expect the denser materials to have sunk to the core, and yet Ceres still maintains a spectral class of "C". Is there perhaps a layer of dusty "regolith" that is leftover from ice-sublimation that maybe lends it this spectral class, despite the fact that it is likely a "differentiated CM-chondrite"?

I had never even considered 'roids as the first stepping stone for a permanent human science base, but Ceres might make excellent sense. A 9 hour rotation period is a little funky, but maybe Ceresians would enjoy a nice after-lunch siesta every 18h "day" (if it's acceptable to call 2-full rotations a "day").

Perhaps most exciting in terms of human exploration potential is from the Nature letter: "Even the minimum mantle thickness is greater than the likely
excavation depths of craters a few hundred km across." So even if the crust is a nasty jumble of pebbles n' dust, a large crater would provide easy access to the water-rich mantle. A nice RTG rover could maybe scratch the bottom of the crater rim and begin melting a hole through the dirty-ice and begin excavating a nice cavern. Spray the walls with ice to make it air-tight, insulate with foam, pressurize and presto! Instant-igloo!

Before I rush out in my covered wagon to stake my claim in the land-rush:

1. is solar-power economically viable from Ceres? How much panels would be needed to crank out the equivelent of the ISS? (ISS = 110kW using 2,500 square metres of solar-panels).

2. is the low gravity a problem for long-term residents? would a gravity-centerfuge be required to keep folks healthy enough for return to earth?

3. is nitrogen available anywhere near the belt?

4. what would be the raison d'etree for a Ceres Base? Watching 'roids? Fuel-depot for outer-solar-system missions?

5. how hard would it be to move nearby small 'roids into orbit for material's processing?

Exciting stuff to dream about!