
Solar System’s biggest asteroid is an ancient ocean world - mooseburger
http://www.nature.com/news/solar-system-s-biggest-asteroid-is-an-ancient-ocean-world-1.21166
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scardine
In "The Expanse" TV show, Ceres is the birth place of the main character,
police detective Josephus Miller.

[https://en.wikipedia.org/wiki/The_Expanse_(TV_series)](https://en.wikipedia.org/wiki/The_Expanse_\(TV_series\))

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colordrops
This show should be more popular than it is. It's relatively hard scifi that
posits a realistic future of solar system colonization.

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posterboy
>hard scifi

It's not, but it takes some inspiration

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pilom
It certainly starts out fairly hard scifi (with the only exception being
Epstein drives) but takes a pretty sharp turn away from that as soon as the
proto-molecule is out and about. It was hard for me not to put the book away
and stop reading the series when the zombies showed up because I was so
engrossed in the realism behind the story that those parts just felt like a
betrayal.

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colordrops
What's wrong with Epstein drives? I haven't read the book, but what is
impossible about them? Is it the amount of energy needed?

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pilom
They are more fuel efficient than anything physics predicts is possible
because they effectively have the max thrust of chemical rockets, combined
with a nearly infinite ISP from using no reaction mass. They mention refueling
the fusion reactors and the steam thrusters, but they never mention reaction
mass for the Epstein drives.

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colordrops
I did some searching and found this:

[https://m.reddit.com/r/TheExpanse/comments/4frz1k/epstein_dr...](https://m.reddit.com/r/TheExpanse/comments/4frz1k/epstein_drive_may_be_real/)

Ignore the original story and the top level comments. Seems there is some
evidence of reaction mass. There is some interesting analysis and basic math
in the comments. I didn't see anything that confirmed or precluded the epstein
drive from being possible. I should get out a pen and paper and work it out
myself.

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pilom
Can we add this to the list of possibilities for human colonies? Moon, Mars,
Ceres. It has less gravity so bones would be harder to maintain but less of a
gravity well to get out of after landing. All that water is pretty darn
appealing for refueling. It is farther away so solar insolation is less but
sounds like it still would be worth it.

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zspade
Well Ceres only has a diameter of 589mi (a little over 1/4 the size of our
moon). It might be a good launchpad for refueling though, given the near in-
significant gravity and apparently plentiful water.

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jboggan
Escape velocity of ~ 500 m/s, that's slower than most rifle bullets travel!

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JoeAltmaier
Its 1/3 of the asteroid belt by mass. So the asteroid belt is what, 1/6 water
by mass?

