OT: Ceres more interesting than previously thought

[dogscoff]

Found this interesting link at Adastra. I've always felt a little sorry for Ceres. Just because it's in the same orbit as the asteroid belt ppl call it an asteroid. I think it should be a planet, and now astronomers are coming round to my way of thinking:

http://hubblesite.org/newscenter/new.../2005/27/text/

OK, lets strap some boosters to that baby, drag it into a more sensible orbit, let all that ice melt, install a bit of atmosphere and then build ourselves a planet-wide low-grav water park and whale sanctuary!

[Caduceus]

Let's not forget the most important reason - Slushie Mining Port.

[Cipher7071]

Interesting...thanks for the link.

At 580 miles diameter, Ceres makes a mighty small planet, and size-wise it's more like many planetary moons. But I suppose, being that it's in orbit around the sun rather than one of the planets, it might qualify. The question then becomes: How big is big enough?

[dogscoff]

Quoth Cipher7071:
At 580 miles diameter, Ceres makes a mighty small planet, and size-wise it's more like many planetary moons. But I suppose, being that it's in orbit around the sun rather than one of the planets, it might qualify. The question then becomes: How big is big enough?

It's about big enough to be circular. It orbits the sun all by itself. Even has a thin atmosphere (probably). It's a planet, I tell you.

I wonder how much of an atmosphere it could hold if we were to introduce one. What if we were to spin it up to get Earth-like gravity? Would that help, or would we have to dome the entire planet to prevent the atmosphere from escaping? It being only a few hundred Ks across, could we put the entire world into a some kind of giant "buckybubble" instead? Engineering on larger scales- ie thousand-kilometre space elevators- are (apparently) feasible with fullerenes. Bubbling Ceres ought to be relatively easy.

wildcard06 intoned:
Let's not forget the most important reason - Slushie Mining Port.

youu'd have to genetically engineer ocean-dwelling bacteria or something that produced blue, rasberry flavour goop...

Mmm... genetically-engineered goop-flavoured blue space-slushie...

[Wolfman77]

Except pluto is 14 times bigger, and it's status as a planet is often debated. With several objects larger than this outside plutos orbit not getting planetary status, it's unlikely that Ceres will get it. The only thing it has going for it is it is on the same orbital plane.

[Will]

dogscoff said:
What if we were to spin it up to get Earth-like gravity?

Well, 'spinning' to generate artificial gravity works because a mass is reacting against centripetal accelleration... so if you hollowed out the inside, this would work. But then, using gravity to hold in atmosphere becomes a moot point, doesn't it?

[dogscoff]

Will said:

Well, 'spinning' to generate artificial gravity works because a mass is reacting against centripetal accelleration... so if you hollowed out the inside, this would work. But then, using gravity to hold in atmosphere becomes a moot point, doesn't it?

Oh yeah, that does make sense.

It fits in with the bubble idea though. I hereby present:
Crazy-assed "it would never work" scifi mega-engineering project #16b: Dogscoff's Orbital Mega-Aquarium.

1- Move Ceres into a nice, warm orbit. Earth orbit would be nice and convenient, as long as you don't cause any nasty tides back home or anything.

2- While Ceres is in transit, tunnel underneath the ice and start mining the rest of Ceres' material. Store this material in orbit for use in step three.

3- Build a huge, transparent, coin-shaped 'bubble' that completely encompasses Ceres. Dimensions are up to you, I have no idea what you'd need. Your bubble can't be spherical, because you're not going to have any gravity at the poles. The coin must be orbitting in such as way that neither the 'heads' nor 'tails' faces are ever exposed to direct sunlight. Build your docking points and airlocks on the 'heads' and 'tails' faces. If you know how deep your ocean is going to be, you'll know how far from the rim to put these. Meanwhile, the sun is melting Ceres' ice into a vast ocean.

4- Spin the whole affair up to a speed where centripetal force exceeds gravity. Your axis is through the centres of the heads and tails faces. All the water will fly off the surface of Ceres and stick to the curved inside edge of your coin, creating a doughnut-shaped ocean. If you were swimming in this ocean, you'd notice that sunlight is coming up from underneath you and the surface of (what's left of) Ceres itself is hanging ominously above your head.

5- Pull a few appropriate chunks of rocks off of what is left of Ceres, blast them into tiny bits (so they dissolve quicker) and then dump them in the water. This will give you salt water (there's nothing wrong with a freshwater ocean, mind you) but more importantly it will also release some of the water's oxygen to give you something to breathe. I think. You will probably have to tinker with the atmosphere quite a bit to get it breathable.

6- That's it. What you've got is effectively a miniature, enclosed Banksian Orbital, although the way it spins and collects sunlight isn't quite the same. Build yourself a few boats, introduce some plankton and fish and stuff and you're away. If you wanted, and if there's actually anything left of it, you could probably put some upside-down buildings up on the lump of Ceres still hovering in the sky above you. (you fly up and dock on the bottom of the the penthouse, then take the lift up to the ground floor ). Alternatively, just remove what remains of it completely, bit by bit, using the material to build luxury liners, surfboards and spaceships. This will make your coin seem lighter and airier, much more Feng-shui than a huge, ugly, scarred and pitted rock o' Doom hovering perpetually in the sky.

Problems:

A- Step one- moving something as big as Ceres from one orbit to another is probably not quite as easy as I make it sound. However I believe it is theoretically feasible, given access to insane quantities of energy and decent spaceflight technology.

B- Step two isn't actually too hard. We might even have the tech to do this now, if someone else could help with the tricky bits (ie steps one, three and four)

C- Step three could be a problem. Materials strong enough for this (and transparent to boot) might not even be possible, let alone obtainable in such massive quantites. Remember your bubble has to support the weight of an entire ocean, it must be rustproof, and be able to withstand the kind of abuse that space throws at it on a regular basis. (radiation, impacts etc)

D- Step four is kind of tricky too by our current standards, but if you can manage steps one and three, this one really is a doddle. In theory, the minimum necessary rotation speed to shed all the water ought to be slightly lower than the speed that would tear Ceres into little pieces, smash your bubble into atoms and give the Earth a pretty planetary ring.

Assuming you've carried out steps one to six successfully, you'll still have some problems.

E- Light. How deep would the ocean be? Too deep to allow any sunlight up to the surface? If this was the case, you could always let some water out until you reach the desired depth. However, you'll always have the problem of keeing the ocean floor clean: As crap builds up down there, it blocks light.

F- Radiation. A certain depth of water would be required to filter out unwanted solar radiation. (That's why you don't want the coin's "heads" or "tails" faces exposed to direct sunlight). This is fine and dandy, but it doens't stop cosmic radiation coming through the heads and tails faces. Maybe these faces could be made opaque. Also, while solar radiation will keep your aquarium's "glass" clear of light-blocking algae, deep-diving creatures (whales, for instance) introduced into the ocean might well get sunburned- not to mention confused- by the sunlight below them. Microwaved Mutant Humpback blubber, anyone?

G- Gravity. I don't know how fast you'd have to spin up your coin to get comfortable gravity, but it's likely to cause some interesting tidal and wind effects.

H- Weather. So the ocean is getting warmed from the bottom up, which ought to create some wierd tidal effects. Also, any water vapour released is going to go... where? Would it all drift inwards and collect in the coin's centre of gravity, freeze and sit there indefinitely, or would it condense and rain back down before it got that far? It all depends of the temperature distributions inside the coin, I guess.

I- Day and night. Is it "day" when the sun is closest to you (ie under your feet) or when it's overhead, with a thousand odd miles of atmosphere, possibly the shrivelled remains of Ceres and a more distant layer of ocean between you and it? How much light would there be on the surface anyway? I think a perpetual (but delightfully sparkly, especially if you introduce some of those luminescent algae) dusky half-light is most likely. You're probably rotating far too fast for any clearly defined day/ night cycle to be comfortable anyway, so maybe this is for the best.

My brain hurts now.

[Strategia_In_Ultima]

.....Is it me or am I the only one who cannot picture Dogscoff's "coin"?

[Makinus]

Can someone draw a diagram? i too cannot picture it...

[dogscoff]

What S_J said is dead right, but here's a diagram anyway because I'd already drawn it.



So, the spin of the coin generates centripetal force, which works much the same as gravity, in this case, sticking the ocean, the atmosphere, the people, fish and everything else to the inside edge of the coin. To blatantly steal an analogy from Iain M Banks' "Consider Phlebas": Imagine that you have a bucket of water with a model boat floating on the surface. Now pick up the bucket by the handle and, holding it at arm's length, start to spin it over your head and back down again. As long as you keep spinning it really fast, the water will never fall out of the bucket, and the boat will not sink, even when the bucket is upside down.

Note that the orbit I've drawn in there could be around Earth or around the sun or even around the moon. Doesn't matter, as long as the sunlight only ever comes in through the bottom of the ocean as shown in the picture. This is because the ocean is what filters out all the harmful radiation.

Note also that my diagram does not show the two circular walls that turn the "wedding ring" I've drawn into a "coin". (If you can't get your head around that, think about what you'd need to add to a wedding ring to turn it into a hollow "coin" shape.) These are the two faces I've been referring to as "heads" and "tails", and they are not transparent. They have two main functions:
1- They keep the atmosphere in.
2- The keep harmful cosmic radiation out. Cosmic radiation comes from all directions, not just from the direction of the sun, so the ocean won't block all of it (unless you are in a submarine.)
Your airlocks and space-ship docking would be on the haids and tails faces.

The dimensions of the coin are beyond my mathematical ken, but you're probably looking at a minimum diameter of about a thousand Ks, and a maximum defined purely by the strength of the materials you are building from. Width-wise, it depends largely on the size of Ceres after you've strip-mined and melted it. Probably in the 200-500Ks range.

You might find that you can have a breathable atmosphere sticking to the ocean in much the same way that the ocean sticks to the coin, but that the centre of the coin, around Ceres, is vacuum (or something close to it.)

Oh, and you don't actually need Ceres in the middle there, by the way. You could take it out if you wanted.

Finally, imagine yourself on Narf's boat. Think about where the sunlight is coming from, and how your surroundings would look. Assuming the coin spins once every 24 hours, where will the light be coming from in 12 hours' time?