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#126 2014-01-04 14:12:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Ceres

I am thinkibg verticle such as a parking garage build up to create upward layers to rise the planets diameter as we taraform giving underground protection until the atmosphere is thicker.

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#127 2014-01-08 07:47:34

Tom Kalbfus
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Re: Ceres

I guess spinning Ceres for gravity is not an option.

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#128 2014-01-08 09:35:44

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
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Re: Ceres

Perhaps a worldhouse could be constructed at the Ceres Synchronous Altitude. I want to put a torus there anyway, with sections that spin to provide more than the 0.028g available on the surface.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#129 2014-03-27 13:47:55

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
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Re: Ceres

Re. the sprinkler effect, I get the impression that the exosphere is no longer mechanically coupled to the lower layers of the atmosphere? Perhaps the atmosphere can reach that point below Ceres synchronous altitude, if it's thin enough? Though, the Martian one isn't much lower in altitude, despite the much thinner atmosphere...

Of course, at that point the atmosphere might be substantially ionised, and thus respond to a magnetic field - either artificial or natural.

Also, if we could get a situation with a hybrid worldhouse, perhaps the atmosphere will precipitate out, fall back down, and then evaporate in the lower levels.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#130 2014-03-27 16:59:46

SpaceNut
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From: New Hampshire
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Posts: 28,747

Re: Ceres

Dawn spent nearly 14 months orbiting Vesta, the second most massive object in the main asteroid belt between Mars and Jupiter, from 2011 to 2012. Dawn has Departed the Giant Asteroid Vesta September 05, 2012 spiraled away from Vesta as gently as it arrived. It is expected to pull into its next port of call, captured by Ceres' gravity -- in late March or the beginning of April 2015.
With NASA's Dawn Fills out its Ceres Dance Card

Dawn will make its first full characterization of Ceres later in April, at an altitude of about 8,400 miles (13,500 kilometers) above the icy surface. Then, it will spiral down to an altitude of about 2,750 miles (4,430 kilometers), and obtain more science data in its survey science orbit. This phase will last for 22 days, and is designed to obtain a global view of Ceres with Dawn's framing camera, and global maps with the visible and infrared mapping spectrometer (VIR).

Dawn will then continue to spiral its way down to an altitude of about 920 miles (1,480 kilometers), and in August 2015 will begin a two-month phase known as the high-altitude mapping orbit. During this phase, the spacecraft will continue to acquire near-global maps with the VIR and framing camera at higher resolution than in the survey phase. The spacecraft will also image in "stereo" to resolve the surface in 3-D.

Then, after spiraling down for two months, Dawn will begin its closest orbit around Ceres in late November, at a distance of about 233 miles (375 kilometers). The dance at low-altitude mapping orbit will be a long waltz -- three months -- and is specifically designed to acquire data with Dawn's gamma ray and neutron detector (GRaND) and gravity investigation. GRaND will reveal the signatures of the elements on and near the surface. The gravity experiment will measure the tug of the dwarf planet, as monitored by changes in the high-precision radio link to NASA's Deep Space Network on Earth.

At this low-altitude mapping orbit, Dawn will begin using a method of pointing control that engineers have dubbed "hybrid" mode because it utilizes a combination of reaction wheels and thrusters to point the spacecraft. Up until this final mission phase, Dawn will have used just the small thruster jets, which use a fuel called hydrazine, to control its orientation and pointing. While it is possible to explore Ceres completely using only these jets, mission managers want to conserve precious fuel. At this lowest orbit, using two of the reaction wheels to help with pointing will provide the biggest hydrazine savings. So Dawn will be spinning up two of the gyroscope-like devices to aid the thrusters.

In 2011, the Dawn team prepared the capability to operate in a hybrid mode, but it wasn't needed during the Vesta mission. It was only when a second (of four) reaction wheels developed excessive friction while Dawn was leaving Vesta in 2012 that mission managers decided to use the hybrid mode at Ceres. To prove the technique works, Dawn engineers completed a 27-hour in-flight test of the hybrid mode, ending on Nov. 13. It operated just as expected.

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#131 2014-05-03 16:47:36

Terraformer
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From: Ceres
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Re: Ceres

Looking at the phase diagram for water, it appears that a temperature of -20c should allow a water vapour atmosphere of 1mb to exist. Obviously, in current conditions this will probably escape quite quickly (but if there is a magnetic field...), but if there is exposed ice, is should be continuously replenished.

However, there's not really much exposed ice, so we'll have to import it. What I'm wondering is, if there is a magnetic field, could we retain such an atmosphere, perhaps over time converting it to an oxygen one?

Unfortunately, we don't get to find out whether Ceres has a magnetic field next year, because that instrument was removed...


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#132 2014-05-03 17:33:35

JoshNH4H
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From: Pullman, WA
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Re: Ceres

I don't see why not.  Have you tried any calculations for the loss rate of oxygen from the exobase?  I suspect the rate might not be as high as some have suggested.  An oxygen-carbon dioxide atmosphere might even be long term stable if you could find a way to cool the wxobase effectively.  Perhaps high altitude nanoparticles to radiate heat away?


-Josh

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#133 2014-05-04 01:23:14

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Ceres

ooorrrr,

instead of using roof no matter made of matter or energy, which to put ON TOP of the atmosphere...

... the atmosphere could be "sponged" INTO the "roof" which to go down to the surface.

Imagine utility fog layer which to contain the atmosphere, to provide artificial "gravity" etc. With envelopes of this even smallest bodies could be terraformed, even empty space could be provided with breathable air, appropriate illumination, 1G "surface/S" ... etc.

Remember Clifford Simac's "Time and again" (1951) where one of the locations was a 1G terraformed asteroid used as a richman's toy-"island" developed as a hunting park?

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#134 2014-06-17 11:33:07

JoshNH4H
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From: Pullman, WA
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Posts: 2,538
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Re: Ceres

Although rather difficult to do in practice, it would be pretty possible to get significant temperature gains on part of the dwarf planet by stopping its rotation.

Currently, the mean temperature on Ceres is 170 K, and the max is 235 K.  I'd like to do some simulation to determine the temperature as a function of time.  All told it really shouldn't be that difficult, more a matter of sitting down and spending an hour with Matlab and my heat transfer textbook (plus some basic assumptions about the surface of Ceres) than too much real thinking.

Hypotheticals aside, however, by my calculations Ceres receives an average of 181 W/m^2 insolation, in comparison to 1366 W/m^2 on Earth.  Assuming that the emissivity and absorptivity have the same value for both bodies (almost certainly false, but is an acceptable initial assumption), if the Earth were tidally locked it would have a peak temperature (ignoring the greenhouse effect) of 394 K.  Ceres would have a peak temperature of 238 K. 

Meanwhile, assuming an "infinite" rotation rate with a changing axis of rotation (I realize this is impossible; What I'm really calculating is the blackbody temperature of these bodies if they were at a uniform temperature) Earth would be at 279 K and Ceres at 168 K.  Earth's true mean temperature is 288 K, so let's say that we can expect an additional 9 K from the greenhouse effect over whichever approximation we're using.  This would raise Ceres' peak temperature to 247 K.  This isn't warm by any means (-26 C, -15 F), but doesn't seem quite so bad to me.  Admittedly, this is a peak temperature, and the actual temperature will likely be lower in most other places.  Having said that, using a 9 K addition for atmospherics, tidally locked bodies should be able to achieve temperatures of at least 273 K all the way out to 2.3 AU.


-Josh

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#135 2014-06-17 14:55:40

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Ceres

Small world, atmosphere might transfer enough heat to the dark side to prevent atmospheric collapse from condensation.

I would also suggest a Dyson orbital segments sphere, where the orbital segments are composed of a framework suitable to extract energy from the solar wind and partially deflect it, and a window glass component would serve to further deflect the solar wind, and also serve as a lid on radiant heat.  Ideally it would also rebound some molecules leaving the upper atmosphere back downward.  The power harvested from the solar wind might be used to generate a magnetic field, or might be beamed downwards to the surface, or some of each.  If this worked OK for Ceres, then perhaps Mars.

A melted surface however presents problems, were blocks of deep ice might float upwards if stimulated by a striking object, or a quake?  Cities on the frozen dark side?  A sea on the sunward side?


Done.

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#136 2014-06-17 17:16:10

JoshNH4H
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From: Pullman, WA
Registered: 2007-07-15
Posts: 2,538
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Re: Ceres

My expectation would be that over time, so much ice would condense on the dark side that the light side would actually be much lower, and the atmosphere would be contained mostly on the warmer, inhabited side.  Though perhaps not on Ceres, with its high scale height and low gravity.


-Josh

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#137 2014-06-18 04:26:49

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Ceres

Ceres. 3% gees.

Tropospheric height 30ish times higher or about 200-300km. No centrifugal bulge if Ceres despinned.

Hydrostatically Ceres could bear as deep of a pit as high of a mountain.

200-300km high, and as wide as the surface allows. Respectivelly - 400km deep and 400km wide pit?

32875726.jpg

I suggest to not only despin Ceres, which is comparativelly easy using orbital tethers and counterweights or simply export of mass via space elevators, but also to DEFORM Ceres.

Hundreds of km wide and deep - almost to the center conical pit, kinda artificial crater.

The excavated material could be used to build walls around the pit and spread over the surface and/or used as ore/materials source.

The pit would be exactly cis-sollar, more exactly then Caloris basin on Mercury.

The air will stay more or less in the pit, only plasmic tech for increasing the atmospheric retention should be applicable on top. Vacuum for the rest of the surface.

The cone lateral surface calculator ( for r=200km , and h=400km ) tells me a figure of 280 000 km2.

A "country" comparable in area with Norway, Italy, UK or Poland ...

If it spirals down as a staricase-manner of open mining pits with (almost) horizontal lane/band, say a mile wide, then the horizontal section lenght will be about 100 000 miles. We mustn't forget that this leaves us with the same area of vertical section of this helix, where structures, entire cities could hang on the wall. ALL the geological layers exposed for utilisation from surface to core/center...

So we are rather talking about a country of the magnitude of France or California!

With this low gees verticality is 30 times less of a factor.

Insolation ( Solar radiation flux ) is 6 to 9 times lower then Earth, BUT eternal noon, thick atmosphere, solid walls ... enough illumination for photosinthesis and for all practical purposes.

Of course inspired by: Larry Niven's Known Space's Canyon planet, but with circular pit - again with sea/lake at the bottom.

I wonder how far from the Sun such an atmospheric puddle could remain habitable with non-amplified insolation?

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#138 2014-06-18 07:36:34

JoshNH4H
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From: Pullman, WA
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Re: Ceres

Pretty far, probably, but there's inevitably going to be some leakage, right?


-Josh

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#139 2014-06-18 07:49:14

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Ceres

Yeah, leakage is unavoidable, but it could be mitigated by either replenishing for which there is practically unlimited material en situ and around, or by atmospheric retention methods or both.

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#140 2014-06-18 09:04:25

JoshNH4H
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From: Pullman, WA
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Posts: 2,538
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Re: Ceres

True.  I seem to recall someone, at some point, saying that Ceres' atmosphere couldn't be contained because it would extend all the way up to the geosynchronous altitude


-Josh

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#141 2014-06-18 09:31:28

karov
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From: Bulgaria
Registered: 2004-06-03
Posts: 953

Re: Ceres

JoshNH4H wrote:

True.  I seem to recall someone, at some point, saying that Ceres' atmosphere couldn't be contained because it would extend all the way up to the geosynchronous altitude

yeah, but not in the pit...

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#142 2015-01-21 19:22:21

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Ceres

The mission is drawing closer and the tantilizing images of a spot dancing as it rotations intriques me as to what it might be.

Short-term variability over the surface of (1) Ceres. A changing amount of water ice although several observations of this body have been performed so far, the presence of surface water ice is still questioned.

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#143 2015-01-22 09:23:09

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Ceres

Yes, that is interesting.  Is it an inni or an outie, or just a stain?

I have been wondering about a potential lucrative method to mine asteroids involving Ceres.

Since it is in the asteroid belt, many desirable sized objects should be available to direct into a collision with the presumed icy mantle of Ceres.

The problem with small rocky asteroids is I think they would be hard to mine. 

However, I am thinking a correctly sized object of a material you wanted, could be caused to impact Ceres, and be enveloped in ice or ice and water.

Then the material is shielded from radiation.  There is then a 4% of Earth gravity field, and of course there is water.  So then that material could be mined by humans with a relative degree of protection from many space hazards.  The materials less valued by Solar Consumer societies could be used locally on Ceres for whatever local purpose their might be.

The more valued materials, could then be sold to Earth or Mars or whoever.

Launching a payload of valued metal from a 4% of Earth gravity field might be financially O.K.

Further, water ice could be put in reflective bags, and impacted on the Moon.  As I recall, if that is done in the shadows or the night, most of the ice will survive, and can be collected.  Daylight would finish it off though.

So, I think Ceres could be a very rich economic entity.


Done.

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#144 2015-01-22 12:12:43

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
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Re: Ceres

I wonder about the possibility of nickel-iron asteroids that have already collided with Ceres... we really need a gravity map of the place in order to detect such lodes.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#145 2015-01-22 12:49:15

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Ceres

That's a good hope.

The difference I might see, is that it is possible that such heavy material will tend to sink down to the core over time.

But a newly impacted item, might have melt water above it, and also still be relatively near the surface, so that excavation might be practical.

But Cow Should I know ?  I've never been there.

I will be glad if we get some clearer view soon.


Done.

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#146 2015-01-22 16:52:30

Void
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Registered: 2011-12-29
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Re: Ceres

With that, mining abilities, whatever they actually are, and a space elevator, and nuclear powered spaceships (Fission or Fusion), then the whole solar system eventually.

Granted, the human race has to find a rational moment also.


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#147 2015-01-23 14:50:38

Tom Kalbfus
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Registered: 2006-08-16
Posts: 4,401

Re: Ceres

Void wrote:

That's a good hope.

The difference I might see, is that it is possible that such heavy material will tend to sink down to the core over time.

But a newly impacted item, might have melt water above it, and also still be relatively near the surface, so that excavation might be practical.

But Cow Should I know ?  I've never been there.

I will be glad if we get some clearer view soon.

I think we can drill or dig to the core of Ceres, digging to the center of that planetoid is equivalent to digging the deepest mines on Earth. So if there is something valuable at the center of Ceres, we could probably get to it.

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#148 2015-01-23 14:52:49

Tom Kalbfus
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Re: Ceres

Void wrote:

With that, mining abilities, whatever they actually are, and a space elevator, and nuclear powered spaceships (Fission or Fusion), then the whole solar system eventually.

Granted, the human race has to find a rational moment also.

Well all that material we dig out of Ceres to build our tunnels, could be shipped to Mars perhaps, I've heard a good portion of Cere's composition may be water, Mars could use that.

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#149 2015-01-23 14:59:47

Tom Kalbfus
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Posts: 4,401

Re: Ceres

I just thought I'd post this, it seems relevant: Especially the part that mentions, "25 percent of Ceres' mass is thought to be composed of water, which would mean the space rock contains even more fresh water than Earth." That would be enough to provide oceans for both Venus and Mars, since Venus' oceans would be shallower and Mars would have just one small ocean in its northern hemisphere. Meanwhile we could hollow out Ceres into a number of habitats, and the first ones will be available to occupy long before either Mars or Venus is terraformed. Basically the waste material from all these excavations would be sent to Mars and Venus. We would have some economic incentive to develop Ceres for immediate settlement and in the longer term send material to Mars and Venus to terraform those planets. Probably a lot of the waste material could be used to build sun shades for Venus as well.

NASA Finds Mysterious Bright Spot on Dwarf Planet Ceres: What Is It?

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SPACE.com
By Calla Cofield
1 hour ago











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NASA Finds Mysterious Bright Spot on Dwarf Planet Ceres: What Is It?
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NASA_Finds_Mysterious_Bright_Spot-892b6e53798653467072a3663e110db4

A mysterious white spot can be seen in the newest images from NASA's Dawn space telescope, which is rapidly approaching the dwarf planet.

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A strange, flickering white blotch found on the dwarf planet Ceres by a NASA spacecraft has scientists scratching their heads.





The white spot on Ceres in a series of new photos taken on Jan. 13 by NASA's Dawn spacecraft, which is rapidly approaching the round dwarf planet in the asteroid belt between the orbits of Mars and Jupiter. But when the initial photo release on Monday (Jan. 19), the Dawn scientists gave no indication of what the white dot might be.

"Yes, we can confirm that it is something on Ceres that reflects more sunlight, but what that is remains a mystery," Marc Rayman, mission director and chief engineer for the Dawn mission, told Space.com in an email. [Photos of Dwarf Planet Ceres] 



The new images show areas of light and dark on the face of Ceres, which indicate surface features like craters. But at the moment, none of the specific features can be resolved, including the white spot.

"We do not know what the white spot is, but it's certainly intriguing," Rayman said. "In fact, it makes you want to send a spacecraft there to find out, and of course that is exactly what we are doing! So as Dawn brings Ceres into sharper focus, we will be able to see with exquisite detail what [the white spot] is."

Ceres is a unique object in our solar system. It is the largest object in the asteroid belt and is classified as an asteroid. It is simultaneously classified as a dwarf planet, and at 590 miles across (950 kilometers, or about the size of Texas), Ceres is the smallest known dwarf planet in the solar system.

The $466 million Dawn spacecraft is set to enter into orbit around Ceres on March 6. Dawn left Earth in 2007 and in the summer of 2011, it made a year-long pit stop at the asteroid Vesta, the second largest object in the asteroid belt.

While Vesta shared many properties with our solar system's inner planets, scientists with the Dawn mission suspect that Ceres has more in common with the outer most planets. 25 percent of Ceres' mass is thought to be composed of water, which would mean the space rock contains even more fresh water than Earth. Scientists have observed water vapor plumes erupting off the surface of Ceres, which may erupt from volcano-like ice geysers.

The mysterious white spot captured by the Dawn probe is one more curious feature of this already intriguing object.

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.
Excitement Builds for NASA Probe's 2015 Encounter with Dwarf Planet Ceres
How NASA's Dawn Asteroid Mission Works (Infographic)
Meet the Solar System's Dwarf Planets

Last edited by Tom Kalbfus (2015-01-23 15:06:37)

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#150 2015-01-23 17:12:36

Void
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Registered: 2011-12-29
Posts: 6,976

Re: Ceres

After proving technological ability, economics would determine if mining could be of profit. I need say no more.

Ya, the white spot is a puzzle, but nicely, there should be new information.


Done.

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