Ceres

tahanson43206 · 2022-10-18 06:45:37

For Terraformer re Mars_B4_Moon #175

Right down your alley!

(th)

Mars_B4_Moon · 2023-08-06 12:35:27

Scientists “excited” about sample from asteroid Bennu arriving in September
https://interestingengineering.com/scie … roid-bennu
A group of Canadian scientists is eagerly awaiting for a sample from the asteroid Bennu that will come September 24 seven years after NASA's OSIRIS-REx spacecraft blasted off Earth to go collect the package.
The craft will now drop a capsule into the Earth's atmosphere containing matter plucked from the surface of Bennu, an asteroid dating from the early history of the solar system.

Calathus: A sample-return mission to Ceres
https://www.sciencedirect.com/science/a … 6520307931

GAUSS -- A Sample Return Mission to Ceres
https://arxiv.org/abs/1908.07731

some older articles From 1 year ago

'Why this Ceres mission could change the search for alien life'
https://web.archive.org/web/20220709055 … alien-life

Ceres’ surface has cold regions that can trap water ice
https://www.spaceflightinsider.com/miss … water-ice/

Terraformer · 2024-07-03 14:29:10

If a sub 1mb atmosphere is desired, held in place by a magnetic field, we should be able to source the mass from Ceres itself. A 100 microbar atmosphere, suitable for screening out micrometeors, would only require 36kg per square metre. Thats a 4cm layer of water across the entire planet that would need to be exposed, at which point it will sublimate and (hopefully) be retained by the magnetic field, at least the oxygen. Such an atmosphere would also screen out a lot of radiation that would be expected to damage the worldhouse roof.

Maybe giving Ceres an atmosphere, albeit a very thin one, will turn out to be a relatively modest task?

Calliban · 2024-07-03 17:38:47

The presence of water on Ceres makes this sort of thing much more achievable.

In fact, Ceres may be key to terraforming Mars, as it is 10% water by mass. Suppose we mount mass drivers on the surface of Ceres. We launch packages of water ice in the opposite direction to Ceres orbital travel, so a portion of the orbital speed is cancelled out. They are given just enough velocity to reduce ther perogee such that it crosses Mars orbit. Eventually, these ice packages will collide with Mars exploding in its upper atmosphere. This will supersaturate the upper atmosphere with water vapour. In addition to creating a strong greenhouse effect, solar UV will break the water into hydrogen and oxygen. The former would rapidly escape Mars, with the oxygen being trapped and accumulating within the atmosphere.

We would need to deliver 7.2E17kg of water to the Martian atmosphere to produce a minimal breathable surface oxygen concentration. That is 82 million tonnes per hour, for 1000 years.

Last edited by Calliban (2024-07-03 17:46:11)

Terraformer · 2024-07-03 18:00:30

That would require strip mining Ceres down to... maybe 600m? Quite significant relative to its size, but could be combined with a paraterraforming project quite well.

A far smaller fraction of that would enable an ozone layer and provide the minimum necessary for advanced plant life I can certainly live with that. Though tbf using solettas to drive Martian water into the atmosphere would be a lot easier.

Void · 2024-07-03 20:42:51

I am going to request your tolerance Terraformer, and Calliban.

I do regard this topic is yours Terraformer.

I have been considering a different type of shell method for large asteroids. The hill sphere of Ceres is interesting.
https://en.wikipedia.org/wiki/Hill_sphere Image Quote:

You can see that the Hill Sphere of Ceres appears to be bigger than that of Mercury.

If a shell were made nearly the size of the hill sphere of Ceres for Ceres, then some method to keep Ceres centered within it may be desired.

If left to no other device, I might suggest magnetic repulsion to keep the Dwarf Planet centered. But I think that a thin atmosphere might give assistance to that desire.

https://en.wikipedia.org/wiki/Gas_kinet … 20molecule.
Quote:

Viscosity
The viscosity of gases is the result in the transfer of each molecule of gas as they pass each other from layer to layer. As gases tend to pass one another, the velocity, in the form of momentum, of the faster moving molecule speeds up the slower moving molecule.

So, I am imagining that the gas density in the interior of the shell would be below the viscous flow level in pressure.

These are things that i have a partial understanding of: https://www.leybold.com/en-us/knowledge … %3E%3E%20d.
Quote:

How to calculate flow rate and types of flow in vacuum physics

I am perhaps looking for a contained molecular flow to, in part, help center the shell around Ceres.

I do not want the shell directly connected to Ceres by cables or towers. Rather, I want an air bearing. The force of the spin would be unfavorable if it had the spin of Ceres. The shell may well fly apart in that case.

Instead, it may be desirable to simulate tidal locking to the sun, with the shell.

But there would be other factors, such as the solar wind and the Photon wind.

But to return to the molecular air bearing on the inside of the shell, if an impactor punches a hole in the shell, only molecules which are traveling in a path from the situation of a bounce would pass though the hole. There would not be a viscous outflow of gas. Robots could continuously repair the shell to reduce that factor as well.

But the solar wind could be a source of gasses if you had openings situated on the sunward side. Or I think it may be possible to make some method to capture the solar wind into the shell.

Composition of the solar wind: https://en.wikipedia.org/wiki/Solar_wind
Quote:

The composition of the solar wind includes12345:
Charged particles: electrons, protons, and alpha particles.
Helium (alpha particles) makes up about 8% of the solar wind.
Trace amounts of heavy ions and atomic nuclei: C, N, O, Ne, Mg, Si, S, and Fe.
The solar wind is a flow of completely ionized gas expanding outward from the Sun's corona.

Anyway, I previously noticed something about the solar wind and Phobos. There is some reason to suppose that the (+) particles of the solar wind may be passing into the interior of Phobos, and it seems that the leeward side of Phobos is of a (-) charge. I may well be reaching too far, but it seems that the leeward side of Phobos is (-) because the heavy atomic Ions cannot get into that space as quickly as do the electrons.

https://screenrant.com/mars-moon-phobos … ime%20ever.

A hope would be to extract electric power from this situation if possible, with a large shell around an asteroid.

And the sunward side with sunlight on it all the time would also perhaps be a source of energy.

The shell would perhaps be substantial enough to support transport devices such as trains, and also to host habitats.

The asteroid could be minded very deeply perhaps even getting into the core in the case of Vesta, I hope.

I don't know but it may be possible to have a more substantial air pressure near the surface of the asteroid, perhaps viscous in nature, attenuating with increased altitude.

I have mentioned air bearing effects and magnetism as methods to keep the shell and the asteroid appropriate so that the asteroid is centered in the shell. But if the shell is larger than the hill sphere it may be possible to hang weight on cables from the sunward side of the shell to keep the shell from being pushed out of place by the solar wind and the photon wind.

It may be that more than one shell could be used. One inside of the Hill Shell could be tied to Ceres and have higher pressure inside of it.

The sunward face of the Hill Shell could have optics to direct sunlight to the asteroid or a more inner shell.

The leeward side of the Hill Shell being very cold, it may be possible to condense escaping gasses of some types on it.

Done

It may be possible to release some Oxygen into the Hill Shell and to conduct the solar wind inside, and to create water, which might condense on the underside of the hill shell in the leeward side.

The solar wind would also inject some Helium and then some trace gasses as well.

Done

Last edited by Void (2024-07-03 21:27:55)

Calliban · 2024-07-04 04:28:47

A 1 microbar equivelent atmosphere on Earth would equate to a column density of 0.01kg/m2. Ceres is outgassing at a rate of ~10^26 molecules per second.
https://www.nature.com/articles/nature12918

If we put in place a mechanism for trapping this gas, a microbar atmosphere would accumulate in about a century. Rocket exhaust would add to this. An artificial magnetosphere created by buried superconducting loops could do this job. The magnetosphere would also deflect solar particles released by coronal mass ejections. Neither the atmosphere or magnetosphere will deflect more than a small fraction of cosmic ray particles. To filter out heavy primary radiation, we would need at least a millibar equivelent column density, or 10kg/m2. That is 1000x more than 1 microbar.

But that might happen surprisingly quickly. As we start mining on Ceres and disturb the crust, hydrated material will be uncovered and will sublime. Rocket traffic will release carbon dioxide and water vapour. Pressurised structures will leak. As Void makes clear, solar wind particles will also be trapped by the magnetosphere.

Last edited by Calliban (2024-07-04 04:46:00)

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Re: Ceres

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